INTEGUMENTAL GLANDS OF CROCODILIA 595 



marked, especially in close proximity to the periphery of the 

 gland. The wall of the fundus consists of three or four layers 

 of elongated cells with oval nuclei; the center of the fundus 

 consists of a mass of irregularly grouped cells, with more rounded 

 nuclei and indistinct walls. 



In an embryo of considerably larger size, about 15 cm. total 

 length, the mandibular gland seemed practically unchanged 

 except that the duct was longer the diameter of the fundus was 

 slightly greater, and there was a small lumen in the center of 

 the fundus where the irregular mass of cells was seen in the 

 preceding stage. 



Figure 35 shows the cell structure of the gland in an embryo 

 at about the time of hatching. The gland has increased greatly 

 in size, though it is probably not yet functioning. The present 

 figure represents a section of the wall of the gland, extending 

 from the surrounding capsule, cp, to the central lumen, lu. 



The capsule now shows both fibrous and muscular layers and 

 will be discussed later. The lumen has the appearance of a 

 small, irregular, torn opening in the center of the gland. 



The wall of the gland consists of about a dozen irregular layers 

 of cells, which, for the most part, have thick, distinct walls and 

 large spherical or oval nuclei. Immediately surrounding the 

 lumen, however, there is a granular mass, in the peripheral part 

 of which indistinct nuclei and cell walls may be seen, as though 

 it were composed of broken down cells. Immediately ad- 

 jacent to the lumen little or no indication of cell structure may 

 be seen. Except for the immaturity of the animal, one might 

 suppose that this central granular mass was the secretion of 

 the gland, formed by the breaking down of the surrounding 

 cells; but as the musk glands are probably of sexual character, 

 they would not be expected to function so long before sexual 

 maturity is reached. 



Figure 36 represents a surface view of a partially evaginated 

 mandibular gland of a 1 -meter alligator. As noted above, the 

 animal has the power of partially turning these glands inside out, 

 so that they have somewhat the appearance of an expanded 

 sea-anemone. In the specimen shown in figure 36, the rough. 



