INTEGUMENTAL GLANDS OF CROCODILIA 597 



of about the same length, the one from the alhgator is more 

 than twice the diameter of the one from the caiman. They have 

 both been freed of the loose, surrounding tissue and are smooth 

 and shiny superficially. 



The gland (B) from the alligator shows the rosette of evag- 

 inated matter, covered with small, usually pigmented, papilla-like 

 projections with an irregular central depression. A section 

 through such a rosette has already been described (fig. 37) for 

 a somewhat smaller animal. The gland proper is white, but has 

 the appearance of a translucent covering over a dark center 

 which shows through faintly. 



The gland from the caiman was not evaginated at the time 

 it was killed, so that no rosette effect is seen. The appearance 

 of the dark center showing through the white capsule, noted 

 above, is very marked in the half of the gland next the duct, 

 so that this half of the gland is distinctly darker than the other 

 half. Possibly it is the pigmented mass of unevaginated pa- 

 pillae, seen in B, that gives this darker color to the half of the 

 gland next the surface. 



Figure 41 is an outline sketch, mostly drawn with the camera 

 lucida, of a vertical section of the submandibular gland of an 

 alligator of a length of somewhat less than 2.5 meters. The sec- 

 tion here represented passed near, but not through, the actual 

 opening of the duct to the exterior. The general shape of the 

 gland proper and of its evaginated portion, ev, is well shown. 

 In the center of the gland is an irregular lumen, In, partially 

 filled by a mass of material to be discussed below. Extending 

 towards the center of the gland from the capsule, cp, may be 

 seen a member of irregular, branching, strands of pigmented 

 connective tissue that divide the gland into a number of ir- 

 regular lobules, lo, whose central lumina open into, or are 

 really a part of, the lumen of the gland, mentioned above. 



Figure 42 represents the cell structure of a section of the 

 gland between the parallel lines shown in figure 41, pi. The 

 inner region only of the capsule, cp, is shown on account of the 

 great thickness of this structure as seen under the moderately 

 high magnification used. 



JOUBNAL OF MORPHOLOGi', VOL. 35, NO. 3 



