For this assignment, I chose to reconstruct two images from Cajal’s staining of nervous tissue and cells through the Golgi method, specifically from the text, “Textura del sistema nervioso del hombre y de los vertebrados” (Cajal 1899). The first image I chose from this collection of Cajal’s illustrations is a portrayal of a developing chick embryo, with various structures such as dorsal motor fibers, ventral roots, and bipolar cells all labeled and outlined. The second image I chose is a portrayal of the primitive epithelium and neuroglia in a newborn mouse, which similarly also has various structures such as the ventral epithelial barrel, astroblasts, and young neuroglial cells, outlined using letters to signify their location.
Image 1:
Image 2:
From the presence of these outlines and labels in these representations of various nervous structures, it is apparent that Cajal intended to present these images as an educational resource for a scientific audience. As a result, each image does contain a caption that seeks to clarify and explain the presence of various structures in each representation. Though Cajal used the Golgi method (which consists of staining nervous tissue using silver nitrate) to visualize the various nervous structures and cells in the tissue, he used pen and ink (the dominant writing utensil at the time) to depict these structures in an illustration. I’ve chosen to substitute pencil (both mechanical pencil and a 2B wooden pencil) in place of ink for my own reconstructions of Cajal’s illustrations, mainly because these implements will make the process of tracing and sketching much more efficient. Though the use of pencil may not contain the definition and sharpness of ink, I have attempted to use my mechanical pencil to mimic these elements by pressing sharply and cleanly onto the paper. Though the use of these utensils may not exactly replicate the use of ink by Cajal, I also believe that the use of pencil contains some benefits in creating a representation of these nervous tissue structures. For instance, the use of pencil allows for the use of techniques such as shading and blending that would otherwise be very difficult to utilize through the use of pen and ink.
In my reconstruction of Cajal’s illustrations, I’ve chosen to employ a combination of tracing and free-hand sketching, which I believe will allow me to replicate Cajal’s use of pen and ink in the most accurate manner possible. I believe that the final product will not only replicate the structures that Cajal detailed and illustrated, but also the various labels and letters that he used, in order to signify various important structures in each of these illustrations.
Though these figures created by Cajal do resemble some images found in scientific papers and journals (as these generally also lack color), one technological change that I believe has impacted our interpretation of this image is its resolution and clarity. Generally, in the modern world, we expect scientific figures to be very clear to the eye; however, this discrepancy may simply be due to the lack of advanced printing technology in the 18th century. Ultimately, Cajal’s illustrations do provide an educational representation of nervous systems in the embryo, and primitive epithelium and neuroglia in newborn mice.
FIELD NOTE 1 OF 3
Date: 2/11/22
People Involved: Fayiz
Location: Room 549 at Duncan Suite 5D
Reconstruction conditions:
It was very late at night and I was alone in my room at Duncan Suite 5D. I turned up the heat on my thermostat because it was a tad chilly outside, and it quickly became very toasty in my very own room. I could hear the constant rumble and growl of my refrigerator, and the static coil whine of my laptop’s fans. I turned on my LED lights and switched on the pink color so it would be easier on my eyes. Also, I could smell the stale smell of cheese in my room, from the cold servery lasagna I had eaten earlier for dinner.
Time and duration of reconstruction:
I spent 2 hours initially reconstructing the image, from 1:00 am – 3:00 am.
Equipment and tools used:
I used my 2B Staedler Pencil to trace the image, my mechanical pencil from Pentel to outline the picture, my laptop to show the image, tracing/gift wrapping paper, and Scotch tape to attach the tracing paper to my laptop. I also used my iPhone to take pictures and a time-lapse of the tracing process.
Subjective factors, e.g., how things smelled/looked/felt:
I initially started with a great deal of hesitation, as I don’t have the most experience in the field of art, and in drawing these complex neural systems. However, I decided to trace the image, at least to provide an outline by which I could continue to draw the image free-hand. As I placed the rough, irregular, and bumpy tracing paper on my laptop, I was a little frightened of the potential of ruining the laptop screen from my pencil marks. I also made sure to place the slick tape on the edges of the tracing paper to adhere to the laptop screen, so that the tracing paper wouldn’t move around all over the place, allowing me to properly trace the minute details of the image. I also made sure to turn the brightness of my laptop and consequently the image to the maximum setting, so it would be easier to see the image under the translucent tracing paper. Even so, when I began to trace the image, I still found it difficult to see the underlying image under the tracing paper, and I had to stretch and press down on the tracing paper at certain parts in order to see the image better to trace from. As I traced the image, I also had some chill music playing in the background, in order to help calm my nerves and to help me reach the flow state of reconstruction. I could also smell the faint scent of graphite as I traced the image and the slightly blunt smell of paper as I was tracing the image. It was quite late at night, so as I continued to trace the image, I felt myself becoming more and more fatigued, my eyes becoming droopy, and it slowly felt more difficult to move my fingers to make the slight tracing marks on the paper, and to focus on the reconstruction of the image.
Prior knowledge that you have:
I’m currently taking a course on Neurodevelopment, and thus I was very intrigued by the prospect of reconstructing Cajal’s illustration of the chick embryo and the various fibers present within this embryo during the process of development. We’ve mostly learned the initial background information about the process by which biological cells develop from a fertilized egg to a zygote to a developing embryo and towards the growth of the organism. To be honest, we haven’t learned much about the development of various motor and sensory fibers within the embryo, but I was still quite interested when I saw the presentation of an embryo and its development, as I had previously seen in my course on Neurodevelopment.
I also have learned quite a bit about Cajal through my previous readings of texts in this course on sensation. I’ve learned that he was a Spanish neuroscientist, who through silver nitrate staining, deduced that the primary cell in the brain and nervous system (the neuron) act in a very discrete and independent manner – with gaps (synapse) between each neuron.
Reflection on your practice:
To be quite honest, the process of tracing and reconstructing Cajal’s image on the chick embryo took much longer than I had initially thought. My initial estimation of the time required was about 30 minutes to an hour, but as I began to trace the intricacies and outlines of each part of the embryo, I quickly realized that it would take me longer as there were several intricacies in the image – specifically with the shape of the various fibers and roots, and the shape of the cells with giant club endings. Also, to prevent any risk of causing damage to my laptop’s screen (as I had placed the tracing paper over the screen in order to trace the image), I used my black Staedler 2B pencil with a very low level of force when tracing. However, as a result, it was often difficult to go back and see the marks that I had created on the tracing paper. I found myself going back and forth, sometimes even re-tracing some of the parts of Cajal’s image, which I’m sure was also a reason why the tracing of the image took much longer than I had initially imagined. In the future, I think a printout of the image with a light behind it, or a more resilient computer monitor/screen may be safer and help me trace the image in a more efficient and timely fashion. Also, though I tried to trace all the intricacies of the image, and all the fibers and cells present, I found it difficult to trace all the cells arrayed across the image and between all the structures in the embryo. Thus, I eventually decided to leave the reconstruction of this part of the image to the next day and to focus on tracing the parts of Cajal’s image of the chick embryo that were easy for me to see through the tracing paper and had distinct outlines and borders.
Photos/video documenting process:
Questions that arise:
This initial reconstruction of the Chick embryo was very intriguing to me – though I’ve seen diagrams and microscopic images of the embryo in textbooks and in my Neurodevelopment class, I had never really seen an image of the embryo quite like this one. To me, Cajal’s illustration of the chick embryo represents a raw illustration of the image that he saw upon the staining of the embryo with silver nitrate. Rather than simplifying the image and taking liberties to make certain aspects of the embryo (such as the position of fibers and cells in the embryo), it appears that he focused on maintaining mechanical objectivity, and in providing a direct representation of a staining subsection of a chick embryo. As a result, without the use of a camera or any similar technology, was Cajal really able to maintain this mechanical objectivity? Isn’t it quite possible that the limitations of the viewing method he was using – microscopy and staining through silver nitrate – lead to inherent biases in themselves that fail to maintain the aspirational standard of mechanical objectivity?
In extension of this concept, do all viewing technologies (cameras, microscopes) contain some sort of inherent bias? For example, traditional microscopes only provide a 2D representation of a sample. In this case, is mechanical objectivity ever truly attainable? (It is suggested by Daston and Galison that it is aspirational, and as thus, may not actually be completely achievable)
FIELD NOTE 2 OF 3
Date: 2/12/22
People Involved: Fayiz
Location: Room 549 at Duncan Suite 5D
Reconstruction conditions:
This time, I reconstructed the image in the middle of the day, and the temperature was slightly warmer in my room, and not as chilly as the day beforehand outside. I was again, alone in my room at Duncan Suite 5D, yet I could still hear the quiet beats of my roommates’ study music from the common room of our suite.
Time and duration of reconstruction:
I spent another 2 hours adding details to the image through free-hand drawing rather than tracing, from 12:00 pm – 2:00 pm.
Equipment and tools used:
I used my Pentel mechanical pencil to add fine details tp the picture and my Staedler 2B pencil to add shading and thicker details to the picture, my laptop to show the image, and thick, white paper to transfer the image onto. I also used my iPhone to take pictures and a time-lapse of the tracing process.
Subjective factors, e.g., how things smelled/looked/felt:
I woke up quite late this morning as a result of my sleeping quite late after a night of tracing Cajal’s image of the chicken embryo. However, after a quick shower and short lunch, I ultimately did feel much more focused, motivated, and less fatigued than I had felt while tracing the image the previous night. In addition, this day, my main objective was to transfer the image I had traced onto the thick, white paper, and to add the minute details I was unable to trace onto the white paper that my final drawing would be displayed on. I also used my sharp-feeling Pentel mechanical pencil this day while adding these details free-hand, and I felt much more confident and comfortable with using this pencil as it’s what I have been using to take notes from the past couple of years in university – thus, I didn’t feel as hesitant and nervous when reconstructing the image as the previous night. As I drew and sketched the various cells in the embryo, I also could smell a fairly pungent, spicy scent, which was definitely from the leftover bok choy noodles I had eaten for lunch. I also much enjoyed drawing on the thick, white paper compared to the tracing paper I had previously been drawing on. The thick, white paper was not only easier to sketch on, but it also felt much less crumply, adding to a more pleasant drawing experience.
Prior knowledge that you have:
In terms of free-hand drawing, I have very slight experience in terms of sketching – most of it is from drawing random objects and items all for fun in my free time rather than from any sort of course or institutional experience. This mostly came into play when I was drawing the various cells in between the fibers and other structures in the embryo, and based on the image of the chick embryo displayed, I drew the cells in a very egg-like, almost eye-like fashion. When drawing these cells, I made sure to draw them in a staggered and crisscrossing pattern that both resembled Cajal’s initial image of the chick embryo and was also more visually appealing to the viewer. Also, since I had previous knowledge from coursework that these were various cells present in the embryo and not just any random structures, I made sure to draw nuclei (dots) in every single cell that I drew in my final representation of the embryo.
Reflection on your practice:
As I discussed before, I much enjoyed drawing and transferring the image of the chick embryo to the thick, white paper. I felt a greater sense of freedom when drawing free-hand the minute details in the embryo, but even though I was still restricted by the initial portrayal of the chick embryo by Cajal, I was still able to take some artistic liberties in the representation of the small cells and minute structures in the picture. Also, since I was no longer tracing the image on tracing paper on top of my laptop, I no longer needed to restrict the amount of pressure I was using when drawing the reconstructed image. Thus, this also afforded me more flexibility in terms of the sketching techniques that I used when drawing the image of the chicken embryo. Since I was also drawing on the thick, white paper, it was also easier for me to see the marks and sketches that I was making on the paper, so I didn’t have to worry about me inadvertently going back and forth redrawing certain sections of the chick embryo, as I had the previous night. Drawing the countless, large amount of cells present in the chick embryo led me to wonder about how all these cells coordinate and come together to form a greater overall organism – how can different assortments of cells and fibers lead to different avenues of cognition and perception?
Photos/video documenting process:
Final Reconstruction:
Questions that arise:
As I discussed above, the presence of various structures and fibers in this chick embryo intrigues me quite a bit – it’s extremely interesting how all these fibers and cells come together to form organisms that perceive via certain fashions and methods. Given that this is a reconstruction of a chick embryo, how specifically are the selection and variation of cells/fibers present different compared to another organism that may have different levels of cognition and perception (according to our human definitions of cognition and sensation)?
In addition, since Cajal produced a 2D representation of the chick embryo through silver nitrate staining of a subsection, how can we be sure that this provides an accurate representation of the various assortment of cells and structures present in the chick embryo, even for the time period? Referring back to the concept of mechanical objectivity, as described by MacLehose, do 2D representations really accurately represent the 3D manner of objects in our world?
FIELD NOTE 3 OF 3
Date: 2/12/22
People Involved: Fayiz
Location: Room 549 at Duncan Suite 5D
Reconstruction conditions:
I again reconstructed the image of the neuroglia of a newborn mouse by Cajal, through the use of tracing. I was once again alone in my room at Duncan Suite 5D, nary with any noise besides the everpresent grumble of my refrigerator and the various noise I could hear from outside or from my common room. Though, since it was also pretty late at night, those noises were relatively muted compared to the vivacious sounds of music and laughter that I might have heard at an earlier time in the day.
Time and duration of reconstruction:
I spent 3 hours tracing the outlines of the image and the neural glial cells, from 11:00 pm – 2:00 am.
Equipment and tools used:
I used my 2B Staedler Pencil to trace the image, my mechanical pencil from Pentel to outline the picture, my laptop to show the image, tracing/gift wrapping paper, thick white paper, and Scotch tape to attach the tracing paper to my laptop. I also used my iPhone to take pictures and a time-lapse of the tracing process.
Subjective factors, e.g., how things smelled/looked/felt:
I was once again quite hesitant when starting the tracing process for my second reconstructed image. After my previous experience earlier with tracing Cajal’s image of the chick embryo, I knew that with the equipment I had at hand, tracing the image on top of my laptop usng the tracing paper would take a longer time than I had anticipated and might also make it more difficult to trace the minute details of the image. Therefore, when tracing the image of the primitive epithelium and neuroglia of a newborn mouse this time, to expedite the process, I made sure to focus simply on tracing the outlines and major structures of the image. After the tracing process, I would then be able to draw the finer details of the image, such as the minute structures of the neuroglial cells, by sketching freehand using my mechanical pencil. Cajal’s image this time was comparatively smaller compared to the previous image of the chick embryo I had reconstructed, but I also realized that the minute details in this image (the neuroglial cells) would similarly also be difficult to trace and instead, I chose to draw these free hand as I had the various cells in the embryo before. In addition, this time, I also chose to go back and tape the thick, white paper to my laptop screen during the sketching process, and I found taping and managing this paper to be a much easier task than handling the tracing paper. Not only was the white paper less crinkly, it was also easier to tape since it was more rigid. However, I did find that this made it more difficult to use the image on my computer as a reference as the thick white paper I had been given by Dr. Li was also much less transparent than the tracing paper.
Prior knowledge that you have:
From my previous courses on biology and neuroscience, I’ve learned that neuroglial cells primarily serve to provide support to neurons and protect neurons from any damage within the central and peripheral nervous systems. However, though I had previously learned about the function of these cells, I had never really considered their structure and significance within these systems. In addition, I found it quite intriguing to visualize the representation of these important cells through the reconstruction of Cajal’s own staining of these structures in a newborn mouse.
Reflection on your practice:
Though this image was much smaller than Cajal’s image of the chick embryo, I nonetheless found it just as difficult to replicate and reconstruct. Though I was able to trace the outlines of the image by using my laptop screen and the tracing paper, I ultimately found it very difficult to visualize the minute structures of the neuroglial cells in the image. I assume that this may be due to my laptop screen having a relatively low brightness compared to other devices, which may have made it difficult to see the image through the tracing paper. Or perhaps it was due to the low resolution of the image, making it difficult to see and distinguish the individual neuroglia in the image. Nevertheless, as a result, I chose to free-hand sketch to the best of my ability, these neuroglial structures within the image, which meant that I did have to take some artistic liberties in terms of the portrayal of these structures. For example, when initially attempting to trace these structures, I initially chose to portray each individual neural glial cell and associated fiber with two lines, rather than an individual line to portray the fiber. Though this may not have been as close to the initial representation of the image by Cajal, I initially thought that drawing the structures in this fashion would make it clearer to represent the darker areas in the image (the young neuroglial cells). However, when drawing the top portion of the image, I realized that this would lead to a great deal of confusion, due to a large concentration of neuroglial cells in this area, and thus, I instead chose to draw these cells and fibers using one line as Cajal originally did in his representation of neuroglia in newborn mice.
Photos/video documenting process:
Final Reconstruction:
Questions that arise:
Cajal’s representation of the neuroglia of newborn mice seems to be a bisected representation of these structures, where the structure is cut perfectly halfway to present a 2D representation of the development of these neuroglial cells and primitive epithelium in a newborn mouse. I’ve done staining in my research lab before, and thus, I really do understand that staining (via the Golgi method) is much easier, and allows for a clear presentation of all the structures present in a select subsection of tissue. In reality, how does this practice of bisection affect how we visualize and perceive these structures?
Moreover, would using a different utensil to trace the image (such as a fountain pen or permanent marker) have made it easier for me to trace the intricate neuroglial cells, rather than having to freehand sketch these details?