154 Inez Whipple Wilder. 



direction tliat the larger portion of the gland lies ventral to the larger 

 giand. This shorter gland is somewhat convoluted and has one 

 branch ; it exhibits several alveolar distensions and in one region (x) 

 is split for a short distance into two tubules, which communicate 

 with each other posteriorly as well as anteriorly. At one point (y) 

 this gland lies in such close proximity to one of the branches of the 

 larger gland as to suggest that a secondary intercommunication is 

 about to arise between two originally independent tubules, a condi- 

 tion which was actually found to exist in a still more advanced stage. 



The larger gland in this specimen shows a great advance in com- 

 plexity of structure. Marked distensions and convolutions occur 

 throughout the gland. The splitting of the entire gland into two 

 parts, already well begun in the 125 mm. specimen, is here almost 

 completely accomplished, while secondary longitudinal splittings seem 

 to be in progress in other regions (z). Many parts show not only 

 alveolar swellings at points of convolutions, but the formation of true 

 alveolar branches. The extreme posterior end shows a peculiar 

 doubling of the gland upon itself, a condition possibly arrived at by 

 a simple convolution, but more probably by an incomplete longi- 

 tudinal splitting. 



The condition shown by a 190 mm. specimen indicates a rapid 

 advance of the developmental processes. Here the right side (Fig. 

 5, f ) shows two glands. The shorter (ventral) one is convoluted and 

 possesses an enormous lumen throughout the middle third of its 

 course ; although by tracing the tube anteriorly, its connection with 

 the epithelium of the introductory nasal passage may be demonstrated, 

 its anterior portion seems to be in a state of atrophy and consists 

 merely of a slender cord of cells with no trace of a lumen. However 

 a secondary communication with the nasal passage has been estab- 

 lished in that the distended middle region of the tubule joins a 

 slender branch of the larger gland, to the complicated mass of which 

 it has thus become annexed. 



The larger gland has a slender duct which divides almost immedi- 

 ately into two tubules, one being the relatively simple and short one 

 which, after making a few convolutions, communicates at its termi- 

 nus with the distended portion of the other gland as above described ; 



