A textbook of obstetrics (1898) (14757638976)

Identifier: textbobstet00hirs (find matches)

Title: A textbook of obstetrics

Year: 1898 (1890s)

Authors: Hirst, Barton Cooke, 1861-1935

Subjects: Obstetrics

Publisher: Philadelphia : Saunders

Contributing Library: Yale University, Cushing/Whitney Medical Library

Digitizing Sponsor: Open Knowledge Commons and Yale University, Cushing/Whitney Medical Library

Text Appearing Before Image:

ze and greater power,however, than the cilia of ordinary ciliated epithelium possess. Spermatic particles first appear in the seminal fluid at aboutthe fifteenth or sixteenth year. There is often, in boys of twelveor thirteen, a seminal discharge, but it contains, as a rule, nospermatic particles. I have had charge, however, of a girl four- Fig. 56. — Hu-man spermatozoa: A,Spermatozoon seen enface; h, head; m,middle-piece; t, tail;e, end-piece; B, C,seen from the side(after Retzius). 66 PREGNANCY. teen years of age impregnated by her brother, aged thirteen, whohad stimulated his sexual development by masturbation. Sper-matozoa often disappear from the sexual discharge of old men,but the age at which this disappearance occurs varies greatly.As a general rule it might be put down as sixty-five, but it willbe remembered that the French engineer, de Lesseps, was afather at eighty-two, and that old Thomas Parr illegitimatelyimpregnated a woman after he had passed his hundredth birth-day.

Text Appearing After Image:

Fig- 57-—a-k, Isolated sperm-cells of the rat, showing the development of thespermatozoon and the gradual transformation of the nucleus into the spermatozoonhead. In g, the seminal granule is being cast off (after II. H. Brown). i—mtSperm-cells of an elasmobranch ; the nucleus of each cell divides into a large numberof daughter-nuclei, each of which becomes converted into the rod-shaped head of aspermatozoon (after Semper). ;/, Transverse section of a ripe cell, showing thebundle of spermatozoa and the passive nucleus (/, n, after Semper), o—s, Sperma-togenesis in the earthworm ; o, young sperm cell; /, the same divided into four ;</, spermatophore with the central sperm-blastophore ; r, a later stage ; s, nearlymature spermatozoa (after Blomfield) (from Iladdon). The Mechanism of the Ejaculation of Seminal Fluid andof its Reception within the Genital Canal of the Female. —The mechanism of ejaculation is only understood by a studyof the anatomy of the penis, which need not

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1898

Whitney Medical Library

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