308 KANSAS UNIVERSITY SCIENCE BULLETIN. 



pull thus executed reflexly causes the head to be raised. When 

 I cut off one antenna from a normal hopper the head was bent, 

 the fore leg extended to where the antenna normally was and 

 the wound rubbed. When the other antenna was removed the 

 insect rubbed first one then the other side of the head where the 

 wound was, going through the different phases of the reflex 

 acts noticed in the case above, first with the front leg of the 

 one side and then with that of the other side. This, in part, 

 proves that Bethe's interpretation of the behavior was correct, 

 and that as the result of the operation a stimulus was created 

 that caused the front legs to remove the irritant. 



Faivre^ considered thesupra-oesophageal ganglion of the beetle, 

 the seat of spontaneous movements, direction, and will ; and 

 Ward^ that in the crayfish it was comparable to the cerebellum 

 of vertebrates, since its loss is followed by the disappearance of 

 spontaneous activity. Lemoine,^ Trevirauus^ and Burmeister*' 

 regard the supra-cesophageal ganglion of arthropods the seat for 

 spontaneous movements ; and Leidig believes that the supra- 

 and sub-oesophageal ganglia together are analogous to the brain 

 of vertebrates. On the other hand, Yersin^ observed that a 

 cricket occasionally moves spontaneously after its brain or 

 supra-oesophageal ganglion has been destroyed. Bethe affirms 

 that the brain, besides being the seat of peripheral nerves, the 

 centre for inhibitory reflex movements, and for controlling the 

 tonus of the muscles, (each half of the brain exerting its influ- 

 ence over its own side,) is not the special centre for spontaneous 

 movements, inasmuch as spontaneous movements were not 

 lost in those arthropods that had their supra-oesophageal gang- 

 lion extirpated. The spontaneous activity after the loss of the 

 brain was, however, least observed in the grasshopper. 



Added to this, Faivre, Ward and Bethe noticed that when the 

 brains of the arthropods that they investigated were extirpated 

 or separated from the other parts of the nervous system, the 

 animals lifted their bodies above the normal level by increased 

 contraction of the flexor muscles, whereby the legs were flexed 



2. Faivre.— Comptes rendus, 1860, T. 51. 



3. Ward, J.— Journal of Physiology, 1879, vol. 2, p. 214. 



4. Lemoiue.— Ann. d. scienc. natur., 1868, T. 9, p, 100. 



5. Treviranus— Die Erscheinungen des Organischen Lebens, Bremen, 1832. 



6. Burmeister.— Handbuch der Entomologie, Berlin, 1832. 



7. Yersin. — Bulletin de la Soc. Vaudoise d. sciens. natur, 1856, T. 5, p. 284. 



