648 THE AMERICAN NATURALIST. (VoL. XXXVI. 
from which they were derived, and the communications with 
the exterior by means of minute ducts are not formed until 
much later. The cells of the early rudiments of glands soon 
begin to be arranged in a more and more columnar manner, 
and after they are arranged in this way the duct to the 
exterior is formed partly from cells of the gland itself and 

partly from the epithelium of the 
E TE r pit. The fully developed gland 
é Pd is simple, saccular, or slightly 
T $ de tubular, with a very small duct. 
" Pd uf s$ : Sometimes glands are pei 
B ^C RC E "um kN b which seem to be parts y 
M s DATY or : kte divided into several portions ; 
eo Pado that is, have one, two, or more 
»- Sete os picts pong whale omens branching off from the 
"Diem wt sey sees main one (Figs: 8, 9). New 
fee Par coe rui Bue glands are formed from the old 
g gland; c, still later stage of developing 
gland. x 20. ones in this way, and although 
these dividing tubules are found most abundantly in half-grown 
specimens, a few of them are often found in the adult. These 
glands are more perfectly formed in those individuals where 
the pits are best developed; but those in a very active con- 
dition, with their lumens widely distended, were only found 
in adult males during the breeding 
season. During the mating season, 
either in fall or spring, these glands 
were very much enlarged in the adult | 
males, their epithelial cells were much 
like low cubes, and the tubules pos- 
sessed large lumens (Figs. 3, 10). 
When these glands were sectioned red male Diemyctylus of neatly 
out of breeding season a very marked sl size, 20, 
contrast was noticed; their lumens were much diminished, 
the cells reached and nearly touched in the center and no 
colloid secretion was present (Fig. 4). These little pits of 
the immature animals or of the adult females have at their 
bases a few masses of cells, or a few small gland tubules, 
which are undoubtedly the beginnings or remnants of the 

Fic. 8. — Section of a tubule from a 
