376 Coe and Kunkel— California Limbless Lizard. 
one or two sharp turns (pl. xii, fig. 26). It is supported anteriorly 
by a delicate mesentery which runs forward toward the ovary in the 
position which the oviduct would occupy if it were fully developed. 
We found it difficult to determine whether this aborted oviduct in 
all cases opens into the body cavity. In the case noted above, where 
it was exceptionally long, such an opening could be distinctly made 
out. Several shorter oviducts, however, were so small and delicate 
at their anterior terminations that serial sections failed to show 
clearly whether a minute ostium was present or not. 
It should be emphasized, however, that this left oviduct corre- 
sponds closely in shape, position and general appearance with that 
terminal portion of the right oviduct which lies posterior to the 
uterus. Its histological structure, too, is practically the same, for it 
is provided with an abundance of compound tubular glands (pl. xiv, 
fig. 37). These glands extend through about two thirds of the 
thickness of the wall of the oviduct, and discharge their secretions 
into its lumen by means of rather large ducts. The epithelial lining 
of the oviduct consists of medium-sized columnar cells, which become 
more or less cuboidal in the glands themselves. In the posterior 
portions of the oviduct the glands increase so greatly in number and 
complexity as to form an almost continuous layer beneath the epithe- 
lium of the lumen. Toward the posterior openings of the oviducts, 
however, the glands disappear, the Jumen becomes much smaller, 
and a distinct layer of circular muscles is formed outside the epithe- 
lium of the lumen. 
The aborted oviduct thus appears to have retained in some measure 
its secretory function, even though it is of little importance in the 
economy of the body. Like many structures which show evidence 
of recent degeneration, this rudimentary organ exhibits a very con- 
siderable variation in length and size in different individuals. While 
its average length is about equal to that of one of the kidneys, yet 
in several instances it has been found to be much shorter, and in the 
single case referred to above it was considerably longer than usual, 
and had a distinct anterior ostium. It is conceivable that in an 
exceptional case it might actually remain of sufficient size to receive 
and support an egg. 
The openings of both oviducts are side by side on the summit of a 
pair of closely united papillee situated in the median line of the body 
on the dorsal side of the thick horizontal partition separating the 
dorsal from the ventral cloacal chambers (pl. xxv, fig. 34 and pl. 
