554 MR. J. B. SUTTON ON ATAVISM. [DeC. 21, 



secreting a thick, viscid, albuminous material, are simplv modifica- 

 tions of the simple recesses found in the bird's oviduct. The third, 

 or uterine section of the oviduct, corresponds to the cervix of the 

 uterus and the vagina. To this we shall return. In the male of 

 the higher mammals, theMiillerian ducts by their fusion give rise to 

 the utriculus. This cavity is formed by that portion of the ducts 

 which in the female constitute the cervix uteri and upper segment 

 of the vagina. 



Excellent confirmatory evidence of this view is afforded by a rare 

 malformation to which the prostate is liable. Instead of the 

 Miillerian ducts disap}iearing after the posterior portions have fused 

 to form the utriculus, a segment of each may persist, so as to give 

 rise to a bicornuate utriculus, in fact a miniature uterus. In rarer 

 instances a Miillerian duct may persist through its entire length. 

 Such a case has been described by Dr. Ord \ There is good reason 

 to believe that some examples described as double ureters were of 

 this nature. 



If the human prostate be examined by cutting it mto slices in the 

 direction of the urethra, at any age after puberty, but much more 

 easily at fiity years, small brownish or black bodies, usually of the size 

 of poppy-seeds, will be detected. These bodies, familiar as prostatic 

 concretions, are, as a rule, very much smaller in young subjects, in 

 whom it is often necessary to scrape the cut section of the lateral 

 lobes of the prostate, and submit the juice to microscojiic examina- 

 tion in order to detect them. Before puberty they are practically 

 absent ; in old age they may attain the dimensions of split peas. 



In number they may vary from twenty to two thousand ; in size 

 from j-^jjj) of an inch to that of a cherry-stone ; in colour bright red, 

 brown, or even black. In consistency they may be soft, hard, or 

 even brittle. Chemically they contain organic matter, about one 

 halfj the rest being made up of phosphate and a small quantity of 

 carbonate of lime. 



For a careful and detailed account of prostatic concretions, the 

 student should consult an excellent paper by Sir Henry Thompson, 

 entitled, " Some observations on the Anatomy and Pathology of the 

 Adult Prostate " ^ 



In the preceding pages an endeavour has been made to prove that 

 the cervix of the uterus and contiguous portion of tiie vagina 

 correspond to the shell-forming segment of the bird's oviduct. The 

 prostate and utriculus correspond to the uterine cervix and upper 

 part of the vagina, therefore they are homologous with the shell- 

 fornriing segment of the bird's oviduct. 



The shell of an egg consists of animal matter impregnated with 

 salts of lime, and is due to the activity of the glands in the third 

 section of the oviduct. Prostatic concretions are due to the activity 

 of the glands lodged in the prostate. The inference is clear that 

 prostatic concretions and egg-shells agree structurally and chemically, 

 and are produced by homologous organs. Thus man has in his 



' Medico-Chir. Trans, vol. Ixiii. p. 11. 



' Medico-Chir. Trans, vol. xl. p. 78 (1857). 



