302 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 37 



and may even disappear. Therefore, it is not surprising that the more 

 labile and rapidly adapting links in the neuron chain for such behavior 

 should fail when the animal is subjected to the gross handling neces- 

 sary in preparation for electrophysiological experimentation. How- 

 ever, in the case of the startle response in the cockroach it has at least 

 been possible to determine the neural site of this instability and adap- 

 tation and to demonstrate some of its properties. The other extreme 

 of this instability is seen in the absence of an equilibrium state in 

 behavior and in the presence of spontaneous activity in many neurons 

 of the insect sensory and central nervous system. The significance 

 of spontaneous activity has been discussed elsewhere (Roeder, 1955), 

 but analysis of its role in behavior has only been begun. 



While solutions to these technical problems are being sought, there 

 is another need in this work that has not been met because of the lack 

 of suitably inclined investigators. Physiological studies can never 

 progress far beyond the speculative stage unless they have a firm 

 morphological basis. Thanks to the fine work of Snodgrass and others 

 it is already possible to describe many insect movements in terms of 

 the muscles and articulations concerned. At the same time, there is 

 very little information on nerve distribution and on the finer internal 

 structure of the insect nervous system that is of value in studies of the 

 sort described above. Work of the caliber and viewpoint shown by 

 Power in his series of papers on Drosophila (1943, 1946, 1948) would 

 be immensely valuable at this point if carried out on larger insects 

 such as the cockroach and praying mantis. The neurophysiologist is 

 often criticized justly for postulating neurons and nerve pathways 

 which have never been seen. However, when he tries to double as a 

 morphologist he usually finds that he would have been wiser to encour- 

 age the interest of a trained specialist. It is my biased opinion that 

 no morphological study could be more interesting or productive at 

 the present time than an examination of the tracts, fiber relations, 

 and synapses in the central nervous systems of the cockroach and 

 mantis. Findings on form could immediately be related to findings 

 on function. 



The interaction of prey and predator contains much of interest to 

 other biological specialists. In this paper speed of response has been 

 considered as a primary determinant of the outcome of this interac- 

 tion, and it has been assumed that speed has been subjected to natural 

 selection. However, it is obvious that many other factors must enter 

 the situation. One such factor, mentioned above, is the accuracy of 

 aim determined during the stalking period. Others, such as the form. 



