340 Eifa Funk Miihsc. 



I have not aimed in this investigation to make a cytological study 

 of the parts of the skin, and the material has not been prepared with 

 that in view. Consequently the question of the production of the 

 secretion in relation to the parts of the epithelial cell or nucleus will 

 not be treated from that standpoint. Further reference to the mature 

 secretion will be made after we will have discussed the stages of 

 gland development. 



Gland outlet. The gland outlet consists of a neck and collar solidly 

 built up from cells, except for a duct which passes through their 

 vertical axis (Figs. 14, 25, 42, 6Y, 78, T9). In the mature gland 

 there is a gradual transition of the neck and collar into each other. 

 The latter has in general the form of a trnncate cone, the base of 

 which rests upon the wall of the acinus, squarely over the lumen 

 of the same. From the top of the cone, the neck continues to the 

 surface at a different angle, assuming more or less the form of a 

 cylinder (Fig. 25-a). 



Concentric zones. The cells of the outlet are arranged in two 

 concentric zones (Figs. 78, 79). The inner and outer zones are dis- 

 tally continuous respectively with the molt stratum and with the 

 outer layers of cells of the transitional stratum of the epidermis. 

 Proximally their position corresponds respectively tc the epithelium 

 and to the muscular part of the acinus wall. The molt cells continue 

 down the duct to about the level of the lower surface of the epidermis. 

 Their short diameter is in this position perpendicular to the duct. 

 The whole layer is intimately bound together (Figs. 70, 71). At 

 about the place where this lifeless layer ends, definite living cells 

 are found ; these continue to the lumen of the acinus, thus completing 

 the inner zone. Their arrangement is radial (Figs. 71-74, 78). 

 Those nearest the molt are more or less polygonal in form, and ar- 

 ranged in a single layer (Figs. 71, 72). As the base of the collar 

 is approached, these cells become more and more elongated and are 

 so shifted in their position as to appear in several layers (Figs. 73, 

 74, 78). A thick pad is thus formed in the collar to which reference 

 will be made in connection with the emptying of the gland. The 

 cells of the outer. zone, beginning at the distal end of the outlet, are 

 but little modified from surrounding cells of the epidermis, except 



