302 JAMES EDWARD ACKERT 



tactile stimuli, for Spallanzani and CXivier observed that bats 

 deprived of sight avoided small objects with accuracy. Cuvier 

 found the wings to be supplied with an enormous number of 

 nerves, and thought that during flight the blinded bat, on ap- 

 proaching the object, sets up air currents, which, reacting on the 

 sensitive patagium and external ears, enable the animal to avoid 

 the obstacle. That the sense of touch is more highly developed 

 in bats than in other mammals was asserted by Schobl ('71), 

 who described 'Terminalkorperchen' at the bases of' the hairs. 

 Moreover, Redtel, two years later, maintained that it is possi- 

 ble for these animals to perceive the slightest difference of ex- 

 ternal air pressure upon their wings. 



The extreme sensitiveness of the integument of these animals 

 and the possibilities of modern technique seemed to justify a 

 further search for sensory structures in their skin. Moreover, 

 at the time this work was begun, no investigator had made an 

 extensive study of the innervation of the skin of bats since Schobl 

 published in 1871 his account of the terminal corpuscles in the 

 flying membrane. 



The work has been carried on in the Zoological Laboratory 

 of the University of Illinois under the direction of Prof. Frederic 

 W. Carpenter, to whom I am indebted not only for his personal 

 interest in the progress of the work, but also for his constant 

 advice and helpful criticisms. 



MATERIAL AND METHODS 



The material for this investigation consisted of forty-one bats 

 of which thirty-one were cave bats (Myotis lucifugus) from 

 Indiana. The remainder, the common red bats (Myotis sub- 

 ulatus), were taken in the vicinity of Urbana, Illinois. 



Most of the material was prepared by an .intra vitam meth- 

 ylene blue method. The blood was washed out of the freshly 

 etherized animal, and a 1 per cent solution of methylene blue in 

 distilled water injected into the arterial system through the heart. 

 After leaving the animal, with its vessels full of staining fluid, freely 

 exposed to the air for oxidation, the fluid was washed out with 



