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Show 554 MR. J. B. SUTTON ON ATAVISM. [Dec. 21, secreting a thick, viscid, albuminous material, are simply modifications 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 Mullerian 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 Mullerian 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 examination 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 POTTO" °f a n ^ncn *° tna* °f 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 " 2. 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 tbe bird's oviduct. The prostate and utriculus correspond to the uterine cervix and upper part of the vagina, therefore they are homologous with the sbell-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. xl. p. 78 (1857). |