46 EVOLUTION AND DISEASE. 
a. 
for we must regard them as being extraordinarily — 
modified as well as highly variable. This may be 
illustrated by examples from widely separated animal 
forms. It will be advantageous to commence with 
the oviducts. In male toads and frogs two slender 
streaks may generally be detected passing from the 
so-called vesicula seminales forwards to the roots of 
the lungs. These thin streaks are the oviducts ; in 
the male they are functionless, and normally remain 
diminutive. It is by no means uncommon to find, — 
especially in male toads, the duct on one or both — 
sides, as well developed as in the female. | 
Professor Howes has described some well-marked — 
instances of the persistence of portions of the 
oviducts in male specimens of the green lizard, 
and in one the entire oviduct persisted as in the 
female. 4 
One of the most noteworthy examples of a persis- 
tent oviduct in a male is that recorded by Mr. J. Da 
Matthews,' which he met with in a skate dissected in 
the Natural History Department of the Edinburgh 
University. In this fish a well-developed oviduct was — 
found on the left side in association with male organs : 
(fig. 23). An examination of the drawing shows | 
clearly enough that this oviduct was not a mere rudi- _ 
ment, but was of the same proportion as would be 
found in a female skate of corresponding size. The 
claspers were present, and about six inches long. | 
This tendency of the oviducts to persist in the male 
is not limited to fish and amphibians, but is manifested — 
* Journal of Anatomy and Physiology, vol. xix. p. 144 
