MANNER OF DEVELOPMENT. 37 



The rodents exhibit a perfect series of gradations between these 

 two extreme states. In all mammals the uterus is developed from 

 two simple primitive tubes, the inferior portions of which form 

 the cornua; and it is, in the words of Dr. Farre, "by the coa- 

 "lescence of the two cornua at their lower extremities that the 

 "body of the uterus is formed in man; while in those animals 

 "in which no middle portion of body exists, the cornua remain 

 "un-united. As the development of the uterus proceeds, the two 

 "cornua become gradually shorter, until at length they are lost, 

 "or, as it were, absorbed into the body of the uterus." The angler 

 of the uterus are still produced into cornua, even in animals as 

 high up in the scale as the lower apes and lemurs. 



Now in women, anomalous cases are not very infrequent, in 

 which the mature uterus is furnished with cornua, or is partially 

 divided into two organs; and such cases, according to Owen, 

 repeat "the grade of concentrative development," attained by 

 certain rodents. Here perhaps we have an instance of a simple 

 arrest of embryonic development, with subsequent growth and 

 perfect functional development; for either side of the partially 

 double uterus is capable of performing the proper office of 

 gestation. In other and rarer cases, two distinct uterine cavities 

 are formed, each having its proper orifice and passage."" No 

 such stage is passed through during the ordinary development 

 of the embryo, and it is difficult to believe, though perhaps not 

 impossible, that the two simple, minute, primitive tubes should 

 know how (if such an expression may be used) to grow into two 

 distinct uteri, each with a well-constructed orifice and passage, 

 and each furnished with numerous muscles, nerves, glands and 

 vessels, if they had not formerly passed through a similar course 

 of development, as in the case of existing marsupials. No one 

 will pretend that so perfect a structure as the abnormal double 

 uterus in woman could be the result of mere chance. But the 

 principle of reversion, by which a long-lost structure is called 

 back into existence, might serve as the guide for its full develop- 

 ment, even after the lapse of an enormous interval of time. 



Professor Canestrini, after discussing the foregoing and various 

 analogous cases, arrives at the same conclusion as that just given. 

 He adduces another instance, in the case of the malar bone," 



™ See Dr. A. Farre's well-known article in the 'Cyclopaedia of Anat- 

 omy and Physiology,' vol. v., 1859, p. 642. Owen, 'Anatomy of Verte- 

 brates," vol. ill., 1868, p. 687. Professor Turner in 'Edinburgh Medical 

 Journal,' February, 1865. 



*" 'Annuario della Soc. del Naturalistl in Modena,' 1867, p. 83. Prof. 

 Canestrini gives extracts on this subject from various authorities. 

 Laurillard remarks, that as he has found a complete similarity in the 

 form, proportions, and connection of the two malar bones in several 

 human subjects and in certain apes, he cannot consider this disposition 

 4 



