Volume 1

A system of gynecology and obstetrics / by American authors ; edited by Matthew D. Man and Barton Cooke Hirst.

Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: A system of gynecology and obstetrics / by American authors ; edited by Matthew D. Man and Barton Cooke Hirst. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    nary manner, and may give rise to a considerable number of spermato- blast#. Each spermatoblast gives rise to a spermatozoon, and in doing so gives [oil J a small mass ot protoplasm, the so-called seminal granule or globule or accessory corpuscle, which appears to have no further func- tion. Fig. 13, a-h, illustrates this process in the rat. (From Haddon): A-H. Isolated Sperm-cells of the Rat, showing the development of the sperma- tozoon and the gradual transformation of the nucleus into the spermatozoon head. In G the seminal granule is being cast off (after H. H. Brown). I-M, Sperm-cells of an Elasmobraneh. The nucleus of each cell divides into a large number of daughter-nuclei, each of which becomes converted into the rod-shaped head of a spermato- zoon (after Semper). N, Transverse Section of a Ripe Cell, showing the bundle of spermatozoa and the passive nucleus (I, N, after Semper). O-S, Spermatogenesis in the Earthworm : O, young sperm-cell; P, the same divided into four; Q, spermatophore with the central sperm-blastophore; R, a later stage; S, nearly mature sper- matozoa (after Blomfield). “ Instead of becoming distinct, the spermatoblasts or incipient sper- matozoa may remain aggregated together (spermospherc or sperm-morula) and surrouud a central non-nueleated protoplasmic mass (the sperm- blastophore), as in the case of the snail and earthworm (Fig. 13, o-s).