A treatise on the science and practice of midwifery . t and homogeneous fluid, in which are float-ing a certain number of granules and epithelial cells, derived fromthe secretions mixed with it, and the characteristic sperm cells and spermatozoa which form its essen-tial constituents (Fig. 40). Thesperm cells are large sphericalvesicles, each containing from twoto eight smaller cells, within whichthe spermatozoa are developed;and, as these soon escape and be-come free, the sperm cells areonly to be detected in the testiclesthemselves, while in semen thathas been ejaculated they are rarelyvisib
A treatise on the science and practice of midwifery . t and homogeneous fluid, in which are float-ing a certain number of granules and epithelial cells, derived fromthe secretions mixed with it, and the characteristic sperm cells and spermatozoa which form its essen-tial constituents (Fig. 40). Thesperm cells are large sphericalvesicles, each containing from twoto eight smaller cells, within whichthe spermatozoa are developed;and, as these soon escape and be-come free, the sperm cells areonly to be detected in the testiclesthemselves, while in semen thathas been ejaculated they are rarelyvisible. The large parent cell,termed by Kobin the male ovule,forms within it several subsidiarycells by the segmentation of itsgranular contents. Within thesesecondarjr cells, or vesicles of evo-lution, which are believed by Kolliker to be developed from thenuclei of the parent cell, the spermatozoa are formed, and beforeejaculation they may be seen coiled spirally in their interior. Theexternal envelope then disappears, and a number of spermatozoa, one. a,h. Sperm cells containing nuclei, each nucleushaving within a spermatozoon, c. Nucleus,with nucleoli, d. Nucleus, with spermato-zoon, e. A cell, with a bundle of spermaticfilaments. /, g, h. Spermatozoa. CONCEPTION AND GENERATION. 85 being formed in each of the secondary cells, may be observed in theinterior of the original parent cell. Eventually that also is absorbed,and the contained spermatozoa become liberated, and move aboutfreely in the seminal fluid. As seen under the microscope, the sper-matozoa, which exist in healthy semen in enormous numbers, presentthe appearance of minute particles, not unlike a tadpole in head is oval and flattened, measuring about g^ptli of an inchin breadth, and attached to it is a delicate filamentous expansion ortail, which tapers to a point so fine that its termination cannot be I seen by the highest powers of the microscope. The whole sperma-tozoon measures from ^-^th to e^tli °f a
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Keywords: ., bookcentury1800, bookdecade1870, bookidtre, booksubjectobstetrics
