Jacob’s images, collectively titled Central Nervous System of Birds, illustrate the primacy of visual observation and literacy in mid-19th-century biological inquiry. Figures 1 through 8 feature views of the heads, brains, and central nervous systems of various birds, namely a parrot, a falcon, an owl, a dove, a rooster, a young swallow, a common sparrow, and a goose. These illustrations do not readily read as the animals they represent, but must be interpreted through a text. The plate’s accompanying legend identifies the species and organ observed in each figure; the perspective taken, such as front or side; and draws attention to anatomical elements within the image. Eyes are particularly highlighted among the sensory organs through the use of labels and the distinctive blue tone used to represent them.
A note on the bottom left of the plate asserts that the illustrations were drawn by French illustrator Nicolas Henri Jacob (1782–1871) from life. This distinction is not unusual for a scientific illustration produced in a time that privileged first-hand observation, and may have served to reinforce the scientific truth value of the images. The lifelike style of representation, including the use of naturalistic colour and of suggested volume in rendering forms, also supports claims to first-hand observation by simulating the experience of direct observation for viewers.
Rather than observing birds as integral entities, these anatomical illustrations invite the gaze to penetrate skin and dissect the bird body in the quest to understand it. While this plate can be interpreted as an extension of human attempts to observe, understand, and control animals under a masterful gaze, its context of publication complicates this relationship somewhat. The placement of this plate in the last volume of the human anatomy collection Traité complet de l'anatomie de l'homme (Comprehensive Treatise on the Anatomy of Man) indicates an interest in comparative anatomy. The author, Jean-Baptiste Marc Bourgery (1797–1849), was a French physician and anatomist who studied under French evolutionary naturalist Jean-Baptiste Lamarck and thus would have likely been familiar with ideas of the evolutionary relationship between humans and nonhuman animals. In seeking to understand biological similarities and differences between human and avian perception, the text implies a certain curiosity about bird vision and perhaps even how birds may see humans. Jacob’s diagrams of the central nervous systems of birds thus invoke a reification of bird vision in empiricist terms, and with it a symbolic return to humans’ unique visually-mediated relationship with nonhuman animals.
Liuba González de Armas