A treatise on the science and practice of midwifery . is innermost layer in the following manner: the nuclei of thesperm-cells proliferate, and from their subdivisions arise the heads ofthe spermatozoa, the bodies of which originate from the protoplasm ofthe cells. By the decomposition of the substance in which the heads ofthe spermatozoa are imbedded the contained spermatozoa become liberated,and move about freely in the seminal fluid. As seen under the micro-scope, the spermatozoa, which exist in healthy semen in enormous num-bers, present the appearance of minute particles, not unlike a tad
A treatise on the science and practice of midwifery . is innermost layer in the following manner: the nuclei of thesperm-cells proliferate, and from their subdivisions arise the heads ofthe spermatozoa, the bodies of which originate from the protoplasm ofthe cells. By the decomposition of the substance in which the heads ofthe spermatozoa are imbedded the contained spermatozoa become liberated,and move about freely in the seminal fluid. As seen under the micro-scope, the spermatozoa, which exist in healthy semen in enormous num-bers, present the appearance of minute particles, not unlike a tadpole in 95 96 PREGNANCY. shape. The head is oval and flattened, measuring about y o^qt °f aninch in breadth, and attached to it is a delicate filamentous expansion ortail, which tapers to a point so fine that its termination cannot be seenby the highest powers of the microscope. The whole spermatozoonmeasures from -^-^ to -g-^-Q of an inch in length. The spermatozoa areobserved to be in constant motion, sometimes very rapid, sometimes more Fig. Section of Parts of three Semeniferous Tubules of the With the spermatozoa least advanced in development, b. More advanced, c. Containing fully-developedspermatozoa. Between the tubules are seen strands of interstitial cells and lymph -spaces. (From a prepara-tion by Mr. A. Frazer.) gentle, which is supposed to be the means by which they pass upwardthrough the female genital organs. They retain their vitality and powerof movement for a considerable time after emission, provided the semenis kept at a temperature similar to that of the body. Under such cir-cumstances they have been observed in active motion from forty-eight toseventy-two hours after ejaculation, and they have also been seen alivein the testicle as long as twenty-four hours after death. In all proba-bility they continue active much longer within the generative organs, asmany physiologists have observed them in full vitality in bitches andrabbits seven or eight
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectobstetrics, bookyear1
