VALIDEZ DEL PERFIL

Illuminating Animal Behavior: The impact of malleable marine stations on

tropism research

On October 20, 1930, a representative of General Electric’s educational sales division sent a letter to Winterton C. Curtis at the Marine Biological Laboratory in Woods Hole, Massachusetts inquiring after two sunlamps sent to the laboratory several months before. “I have been asked by the Sunlamp Sales Division” wrote A.C. Stevens “whether or not these have yet been put into service. If so, we should like very much to know in what way they will be used and something of the results obtained or

expected.”331

It is clear from the letter that Stevens has no understanding of the possible uses of a sun lamp at a marine station, stating merely that the lamps were sent on the recommendation of Dr. W.R. Whitney, the director of the research laboratory of General Electric. But, then, why would Whitney believe that a marine station required, or at least could find some use for, a set of sun lamps?

Marine stations, located at water’s edge, might seem like a counterintuitive place to send artificial sunlight, but beginning in the late 19th century, the rise of tropism studies on aquatic invertebrates brought new lighting technologies and spaces into aquatic laboratory spaces. Identification of UV in sunlight, and the link between UV and medical properties (including disinfectant and overall health), made sunlamps and their artificial lighting precursors prominent in physiology laboratories.332 But these

instruments were also being utilized in animal behavior studies. Animal behavior

331

A.C. Stevens to W.C. Curtis Oct. 20, 1930 “1930 No Order” Mekel Jacob Collection. Marine Biological Laboratory Archives: Woods Hole, MA.

332 _{Philip E. Hockberger, “A History of Ultraviolent photobiology for humans, animals and}

190 researchers brought gas burners, carbon arc-lamps, incandescent bulbs and Nernst

glowers into marine laboratories in a bid to create a controlled research environment for the study of phototropism behavior (animal reaction to light stimuli). Tropism research combined available invertebrates, new lighting technologies, specially crafted glass enclosures, and specialized dark rooms to study tropism behavior in these spaces.

In Philip Pauly’s 1987 biography of Jacques Loeb, he dedicates an entire chapter to the tropism debate in animal behavior between Loeb and Herbert Spencer Jennings. Loeb advanced research in the mechanistic reactions of animals to light and sought to establish a mathematical law to predict and therefore manipulate these tropisms. Jennings disagreed with Pauly’s mechanistic and highly quantified thesis of tropic behaviors, and theorized that organisms followed a “trial and error” form of movement based on “fright” response in light reactions. According to Jennings, each individual reacted differently depending on their internal physiology at the moment of stimulus.333

As shorthand, the Loeb-Jennings debate nicely encompasses many of the ideological issues in phototropism studies during this period. Loeb and Jennings each give voice to opposing theories about phototropic behavior.334 While historians have focused on the ideological differences between the two- Loeb was uninterested in theoretical concepts such as the evolution of thought, behavior, or consciousness while Jennings sought to link his studies with those exploring these larger concepts- I believe a

333 _{Pauly, Controlling Life; Philip Pauly, “The Loeb-Jennings Debate and the science of animal behavior”}

Journal of the history of behavioral sciences 17:4 (Nov. 1981): 504-515; Arnold E. S. Gussin, “Jacques

Loeb: The man and his tropism theory of animal conduct” Journal of the History of Medicine and Allied

Sciences 18:4 (1963): 321-336. For information on Jennings’ career, see Sharon Kingsland “A Man out of

Place: Herbert Spencer Jennings at Johns Hopkins, 1906-1938” American Zoologist 27:3 (1987):807-817.

334 _{E.D. Congdon presents Loeb and Jennings as the leaders of opposing theories of phototropism: trial [and}

error] and phototaxia and places Jennings and Loeb as the head of these two groups. His paper provides a fantastic primer for those who wish to see the alignment of researchers under these two banners. E.D.

Congdon, “Recent studies upon the locomotor responses of animals to white light.” Journal of

191 more fruitful approach to examining this debate, and its impact on the field of tropism studies in animal behavior , and animal behavior studies in general, is by identifying the changes in the experimental process enacted by these opposing theoretical beliefs. In conjunction with their theoretical differences, Loeb and Jennings focused on separate experimental variables and thereby developed different experimental methods.

Loeb and Jennings each concentrated on experimental variables that mirrored their theoretical convictions. Loeb favored a highly quantified approach, focusing on experimental variables such as light intensity and technological readings while paying little attention to individual specimen behavior and less attention to alternate forms of experimental organisms or species. Jennings published highly qualified work that examined individual test subjects’ tropic reactions, paying close attention to physiological understandings of the organisms and their natural behavior patterns. Although Pauly suggests that the “fitful and inconclusive” debate ended when Jennings prevailed and interest in invertebrate behavior waned, researchers retained interest in the subject of tropisms and examinations of phototropic behavior expanded into general animal behavior studies.335 Disciples of each man continued to test their respective mentors’ theories and refine their experimental techniques.336

These methods, including advanced lighting technologies, advanced glassware, animal prep techniques, and the process of reporting findings, developed throughout the Loeb-Jennings debate and researchers integrated them into the study of tropisms.

335

Pauly, Controlling Life,119.

336_{In fact, Loeb published his largest work on tropisms Forced Movements, Tropisms, and Animal Conduct}

(Philadelphia and London: J.B. Lippincott and Co.,1918). At this time, he was still debating Jennings (even though Jennings had indeed moved on from animal behavior into genetics work). Loeb carried a major grudge against Jennings personally as well as professionally. Sharon Kingsland remarks on the relatively amazing fact that Jennings career was unscathed by his brush with Loeb. Kingsland, “A Man out of Place,” 807-8.