THE SEXUAL OKGANS. 625 



rotatory, quivering changes of place, during which the head or body 

 always precedes, that these elements of the semen were formerly 

 regarded as animals. The duration of the movements depends upon 

 various circumstances. In the dead body they are riot unfrequently 

 perceptible, even 12-24 hours after death (on one occasion Valentin 

 noticed faint motion at the end of even 84 hours), and in the female 

 genital organs in the Mammalia, they exhibit motion even after seven 

 or eight days. Water at first renders the motions more lively, but they 

 soon cease, and the filaments are not unfrequently curved in a loop- 

 like form. Blood, milk, mucus, pus, syrup, and a diluted saline solu- 

 tion usually have no injurious effect ; but it is otherwise with urine and 

 bile, the former particularly, when it is strongly acid or much diluted. 

 All chemical reagents, acids, metallic salts, caustic alkalies, &c., cause 

 the motion to cease, as do narcotics when they act chemically upon the 

 filaments, or are too much diluted.* 



The formation of the spermatic filaments and of the semen, it is true, 

 usually ceases in old age, although they are not unfrequently found in 

 men of 60, 70, or even 80 years of age, and even accompanied though 

 this, it must be confessed, is an unusual phenomenon with the procrea- 

 tive faculty. After diseases, the spermatic filaments are as often found 

 to be present as absent ; and, with respect to the cause of their defi- 

 ciency, only this much can be stated, that it appears to depend princi- 

 pally upon impaired nutrition. f 



* [Chloroform exerts the same influence upon the spermatozoa as it does upon all 

 motile tissues in animals and plants. The spermatozoa of the Frog, when exposed to the 

 dilute vapor of chloroform, gradually cease to move, regaining their motile property upon 

 exposure of the fluid to the air (at any rate many of them), and the filaments thus re- 

 vivified, appear to retain all their impregnating power. TRS.] 



f [The origin and development of the spermatic filaments have lately been accurately inves- 

 tigated by Dr. Burnett (vid. Mem. of Americ. Acad. of Arts and Sciences, v. i., 1853). From 

 an extensive series of researches in the vertebrate animals, Dr. Burnett concludes that the 

 morphological changes in the sperm-cell, preceding the formation of the spermatic filaments, 

 are identical in their character with the changes in the ovum, which are antecedent to the 

 formation of the new being. When the generative function begins to be developed, 

 the character of the epithelial cells, lining the tubules, is modified. The cells pass to 

 a higher degree in function, but do not undergo any change in structure, except a slight 

 increase in size. In this condition, they divide and subdivide, by a process similar to the 

 segmentation of the yelk, until they are entirely converted into a mulberry mass. A lique- 

 faction of the segmented contents into a minute granular blastema then ensues, and from 

 this the spermatic filaments are developed. In the Plagiostomes, Dr. Burnett was able 

 to observe the disappearance of the mulberry mass, and its replacement by a fasciculus 

 of spermatic filaments, although the exact metamorphosis by which the granular cellular 

 mass formed the bodies of the spermatozoids could not be detected. The spermatic filaments, 

 Dr. Burnett thinks, are not formed, as stated by Kolliker, by a deposit from the contents of 

 the sperm-cell or nucleus, but by an elongation of the cell or nucleus itself. The body of 

 the spermatozoid is developed from the cell, whilst the tail is probably subsequently formed 

 by an accumulation of minute granules. 



The absence of these spermatic particles does not always, as above stated, depend upon 

 impaired nutrition. M. Gosselin (Archives Generates de Medicine, Sept., 1853) has noticed 



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