46 EVOLUTION AND DISEASE. 



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 vesiculae 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. 



One of the most noteworthy examples of a persis- 

 tent oviduct in a male is that recorded by Mr. J. D. 

 Matthews, 1 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- 2 3)- 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 

 1 Journal of Anatomy and Physiology, vol. xix. p. 144* 



