636 SPECIAL HISTOLOGY. 



an excitement of the nervous system has caused an increased flow of 

 blood to the testis. There are no certain facts in favor of an absorption 

 of the semen when formed, which could only take place in the vasa de- 

 ferentia and vesiculce seminales ; for what is observed in animals, after 

 the rutting season is over, has no reference to this point ; and the very 

 circumstance, that in the situations above-mentioned, no traces of disin- 

 tegration of the semen are ever found, appears to be very much opposed 

 to such a supposition. At the same time, however, it is perhaps unques- 

 tionable, that without seminal evacuations, a formation of semen may be 

 possible ; for it is sufficiently established, that a rich, heating diet, and 

 an unsatisfied sexual excitement, often produce a turgescence of these 

 organs, attended with painful sensations, and most probably with a for- 

 mation of semen. The subsequent removal of this fulness does not, 

 however, appear to me incontestably to prove any absorption, because a 

 difference in the quantity of blood in the testis, and the passing of the 

 semen into the v. deferentia are sufficient to account for the restoration 

 of the usual condition. The fluid constituting a seminal emission is not 

 pure semen, but in great part the secretion of the vesiculce seminales and 

 prostate, and affords no criterion by which to estimate the energy of the 

 secretion of the testes. The formation of the semen itself certainly does 

 not proceed rapidly and copiously, as might be concluded from the rela- 

 tively small quantity of blood contained in the testes, and from its slow 

 motion in them, necessarily consequent upon the anatomical conditions; 

 and as is also evident from the fact, that after a few previous emissions, 

 even in the most vigorous organisms, a certain time is requisite for the 

 preparation of a fresh secretion. The secretions of the accessory glands 

 are perhaps simply intended for the dilution of the semen. 



That the seminal filaments are not animalcules, but elementary parts 

 of the male organism, it is useless at the present time to attempt to de- 

 monstrate ; although it is still as much as ever unknown, and will not 

 easily soon be ascertained, what is effected by their curious movements, 

 which are obviously intended to convey them to the ovum, from the ute- 

 rus, which they probably reach in fruitful congress. Nor, from the ex- 

 periments of Prevost, Dumas, Schwann, and Leuckart, and the later 

 researches of Newport (Phil. Trans. 1851, 1), can the least doubt be en- 

 tertained that they are the true impregnating agent, and for the purpose 

 of impregnation must necessarily come in contact with the ovum. The 

 circumstance that motile spermatic filaments alone possess the fertilizing 

 property, and, according to Newport, that the effect upon the ovum takes 

 place immediately upon the contact, although a short duration of the 

 contact of the spermatic filament with the ovum is necessary to render it 

 efficient, also shows, as it appears to me, that they do not act by afford- 

 ing any material substance to the egg, but in consequence of their ex- 

 citing actions in it, as bodies in a state of peculiar activity. In my first 



