242 GEO. H. BISHOP 
(A\p 
vas deferens, takes the form of a square-root sign C E 
? 
D 
text fig. 3), in which the perpendicular stem represents the gland, 
the horizontal arm the vas deferens, and the portion of the per- 
pendicular below the arm, the protrusion which meets the ejac- 
ulatory duct. 
This change in shape distorts the course of the fibers of the 
longitudinal and circular muscle layers. Their original course 
along and around the U-shaped axis of the original fundament is 
modified in conformity with the change from this axis to that 
of the mature gland. Where the base of the gland protrudes to 
meet the ejaculatory duct, the muscle layers are carried out in 
its wall and greatly thickened, investing the end of the duct 
and the base of the gland with a heavy and complexly arranged 
musculature (pl. 1 and pl. 3, fig. 10). Fibers of the outer longi- 
tudinal layer still pass longitudinally as before on one side, the 
dorsal and medial, as far as the vas deferens, and on the other 
side, the ventral, down to the basal tip of the gland whence 
leads the ejaculatory duct. From here they pass anteriorly 
again on the dorsal side to the vas deferens. On the lateral 
aspects of the base of the gland, the fibers of this layer must 
pass across in a transverse direction to reach the vas deferens. 
The fibers of the circular layer are correspondingly distorted. 
This layer still encircles the gland above the entrance of the vas 
deferens (text fig. 3, 2,’ y,” 2’) and encircles the end of the vas 
deferens itself (x, y, 2) at its juncture with the gland. But 
below the region of the vas deferens entrance, these circular 
fibers, whose fundamental course may be considered to have 
been in concentric rings about the end of the vas deferens, are 
distorted by the base of the gland having protruded toward 
the ejaculatory duct (2’, y’, 2’). They extend toward the base 
of the gland in the same general direction as the longitudinal 
fibers of the same region, but criss-crossing them diagonally 
(pl. 3, fig. 10). 
