ANATOMICAL FEATURES 



was used in reference to the female organ. The use of the word "ovary" was 

 introduced by Steno in 1667, and also by de Graaf (fig. 1) in 1672 in his 

 work on the female generative organs. To quote from de Graaf: "Thus, the 

 general function of the female testicles is to generate the ova, to nourish 

 them, and to bring them to maturity, so that they serve the same purpose 

 in women as the ovaries of birds. Hence, they should rather be called ovaries 

 than testes because they show no similarity, either in form or contents, with 

 the male testes properly so called." (See Corner, '43.) From the time of 

 de Graaf the word "testis" has been restricted to designate the male organ 

 essential to reproduction. 



The phrase "essential to reproduction" does not describe fully the impor- 

 tance of testicular function. As we shall see later on, the testis not only assumes 

 the major role in the male's activities during the period of reproduction, but 

 also, in the interim between specific reproductive periods, it governs in many 

 instances male behavior leading to protection and preservation of the species. 

 Thus, the testis is the organ responsible for maleness in its broader, more 

 vigorous sense. 



B. Anatomical Features of the Male Reproductive System 



Before endeavoring to understand the general functions of the testis in re- 

 lation to reproduction, it is best to review some of the structural relationships 

 of the testis in the vertebrate group. 



Fig. 1. Reinier de Graaf. Born in Holland, 1641; died in Delft, Holland. 1673. Author 

 of important works on the generative organs of the female. Described the Graafian fol- 

 licle in the ovary of mammals but erroneously believed it to be the mammalian egg. (From 

 Corner, '43.) 



