554 MR. J. B. SUTTON ON ATAVISM. [Dec. 21, 
secreting a thick, viscid, albuminous material, are simply 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 disappearing 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 into slices in the 
direction of the urethra, at any age after puberty, but much more 
easily at fifty 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 microscopic 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 z757 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 
half, 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 the 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 homolegous with the shell- 
forming 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 
1 Medico-Chir. Trans, vol. lxiii. p. 11. 
2 Medico-Chir. Trans. vol. x]. p. 78 (1857). 
heh 
