INNERVATION OF INTEGUMENT OF CHIROPTERA 305 



shows that the general direction of these strands and fibers is 

 parallel with that of the stratum Malpighii. While it is not pos- 

 sible to determine a boundary between the stratum papillare 

 and the stratum reticulare, yet the deeper connective tissue 

 bundles of the latter are obviously more loosely interwoven 

 than those of the superficial layer of the corium. As in other 

 mammals, the corium contains blood vessels, hair follicles, seba- 

 ceous glands, sudoriparous glands, striated and smooth muscle 

 fibers, nerve trunks, medullated and non-medullated nerve 

 fibers, tactile corpuscles, ajnd nerve endings. The last three 

 structures mentioned will be described in detail later. 



As has been noted, the upper lip of the bat is richly supplied 

 with skin glands. One type of these, the modified sweat gland, 

 differs somewhat from the typical sweat gland, so a description 

 of its structure may not be out of place here. Compared with 

 a hair follicle, this gland is enormous in size. It consists of a 

 long, uncoiled secreting portion with an extended funnel-shaped 

 duct. The secretory portion is lined by a single layer of colum- 

 nar cells with finely granular protoplasm and round or oval 

 nuclei (fig. 3, cc). Leydig, Schobl and Sabussow ('10) have 

 called attention to the fact that these large modified sweat 

 glands (in the flying and interfemoral membranes) have a coat- 

 ing of smooth muscle fibers, which, by their longitudinal course, 

 cause a slight spiral striping of the gland. This coating of muscle 

 fibers (fig. 3, mf) lies between the layer of columnar cells and an 

 external covering or basement membrane (fig. 3, bm). The 

 latter is homogeneous and without nuclei. The duct of the gland 

 is lined throughout by short, somewhat irregularly cubical cells, 

 arranged in a single layer, and surrounded by a delicate basement 

 membrane. Not infrequently secretion products are found in 

 the lumina of the glands. The products are more or less similar 

 in appearance to what Wimpfheimer ('07) terms degeneration 

 products ('detritus') found in uncoiled sweat glands in young 

 moles. 



It is worthy of remark that pigment cells occur in the corium 

 both of the body integument and of the flying and interfemoral 

 membranes (fig. 2, pc). In, the corium of the integument they 



