332 JAMES EDWARD ACKERT 



that these condensations are perceived by the blinded animals 

 chiefly by means of the free nerve end-knobs in the epidermis, but 

 also in part by the superficial nerve rings of the hair follicles. As 

 the flight of these animals, when close to objects, is tolerably slow, 

 it seems probable that such sensory impulses could be transmitted 

 to the central nervous system, and motor ones be carried back to 

 the muscles of the wings in time for the bats to avoid obstructions 

 in their way. 



SUMMARY 

 GENERAL STRUCTURE OF THE INTEGUMENT 



1. The integument of Chiroptera has a general covering of 

 hair, although the soles of the feet, the mammae, the external 

 genitalia, and the distal parts of the ears and of the flying and in- 

 terfemoral membranes are almost naked. 



2. The skin consists of epidermis and corium. The epidermis 

 is made up of a well developed stratum corneum (whose deepest 

 layers, the stratum lucidum, can be seen distinctly only in the 

 palmer and plantar regions) and of a Malpighian stratum. In 

 the integument of the body the Malpighian stratum contains the 

 three layers commonly found in the mammalian skin, while this 

 stratum in the membranes consists at most of but two layers, and 

 frequently of but one. The corium is composed of an external 

 stratum papillare, containing both simple and compound papillae, 

 and of an internal stratum reticulare. 



3. Pigment granules are abundant in the Malpighian stratum, 

 while in the stratum corneum they are much less numerous. In 

 the flying and interfemoral membranes more pigment is present 

 in the dorsal than in the ventral duplicature of the epidermis. 

 Isolated pigment cells are of frequent occurrence throughout the 

 corium. 



NERVE LAYERS OF THE INTEGUMENT 



1. In the integument and subcutis of the body three layers of 

 nerves are found. The first (most internal) layer consists of 

 medullated trunks in the subcutaneous tissue. By dichotomous 

 branching these nerves break up into a loosely intertwined mesh- 

 work, consisting of an enormous number of medullated nerves, 



