The Lateral ISTasal Glands of Amphiuma. 153 



of this division. The constrictor and dilatator muscles are already 

 well developed and each tubule opens anteriorly into its respective 

 nasal passage through a slender duct which has the same relationship 

 to the nasal muscles as described above in the large adult. 



A slightly older stage, 78 mm. long, shows a larger number of 

 tubules and an increase in the complexity of structure of the gland. 

 This specimen has two independent tubules upon the right side and 

 three upon the left (Fig. 5 b), all opening in close proximity upon 

 the anterior surface of the spiral fold. In each group the tubule 

 having the most anterior and dorsal orifice is the shortest. In the 

 group of three the middle one is by far the longest. All of the 

 tubules exhibit convolutions, and the long tubule of each side has one 

 or more branches. 



An 80 mm. specimen studied by dissection shows very similar 

 conditions on both right and left sides (Fig. 5, c and d). Here 

 there are two independent tubules upon each side, one, the more 

 ventral, being in each case much shorter than the other. The longer 

 gland shows a considerable complexity of structure, the development 

 of alveolar-like swellings, and the tendency toward a longitudinal 

 splitting of various regions being noticeable features. The result of 

 the latter process is the very curious condition in which the whole 

 gland ajipears to be splitting longitudinally into two main parts. 

 Thus in d four regions indicated by x show complete separation, 

 while the other parts still remain in communication. 



A 125 mm. specimen shows upon the right and left sides two and 

 three tubules respectively. Upon the right side the more dorsal gland 

 is the extensive, complicated one; upon the left side the middle and 

 the ventral (posterior) one form a complicated glandular mass, while 

 the more dorsal tubule is short. The series is not sufficiently perfect 

 to allow one to work out accurately the course of the middle and 

 ventral tubules. As nearly as I can determine, however, the middle 

 one contributes by far the longer and more complicated portion of the 

 glandular mass. 



One side only, the left, of a 150 mm. specimen was sectioned (Fig. 

 5, e). In this there are two independent glands; the shorter one has 

 the more anterior and dorsal orifice, but it bends about in such a 



