EMBRYOLOGY. 173 



EMBRYOLOGY. 



REPRODUCTION. 

 What is a species? 



It is a class of organized beings in which the individuals 

 composing it die off, but which nevertheless repeats itself and 

 maintains its complement by the continued accession of similar 

 forms. 



What is reproduction? 



It is the process by which a species is perpetuated, notwith- 

 standing the limited existence of the individual members. 



What law governs the reproduction of species ? 



The young are of the same kind as their parents. By this law, 

 which is so commonly observed as to seem a truism, is maintained 

 the anatomical identity of individuals of a species, as well as the 

 physiological fact of an unbroken continuance of the species by 

 reproduction. 



What is sexual generation? 



It is reproduction of a species by a union of elements produced 

 separately by the female and the male. The female produces the 

 ovum or egg, which is capable of being developed into a living 

 offspring only when it is fecundated or impregnated by the seminal 

 or spermatic element from the male. 



What are the organs of generation of the female ? 



They consist of two ovaries, in which the ova are formed, and 

 their oviducts or Fallopian tubes, which carry the ova to the womb, 

 in which they may develop if fecundated by the male ; and the 

 vagina for the reception of the male organ in copulation and for 

 the subsequent discharge of the foetus (Fig. 51). 



Describes the ovaries. 



They are two organs lying one on each side of the uterus, in the 

 folds of the broad ligament. In size they are about 1? in. long, 1 

 in. wide, and in. in thickness. Besides lying between the layers 

 of the broad ligament, they are stayed in their position by an at- 

 tachment to the fundus of the uterus and to the fimbriated extrem- 

 ity of the Fallopian tube. 



