334 M. Treviranus on the Organized Bodies in 



" To these earlier observations I can now only add a third, 

 which appears to me deserving of attention. 1 think I have dis- 

 covered that the organized parts of semen are not in reality ani- 

 mals, but bodies analogous to the pollen of plants ; that these bo- 

 dies form on the internal surface of the vessels engaged in the 

 secretion of the seminal fluid ; that in many animals they are 

 furnished with peduncles ; that for peduncles they have the fila- 

 ments of a layer of extremely delicate fibres with which the sur- 

 face of the secreting vessels is covered ; that at the period of their 

 maturity they detach themselves from these surfaces, sometimes 

 with and sometimes without the peduncles ; that they appear to 

 contain the proper fructifying matter, and that in some animals 

 they discharge their contents within the testicle, and in others not 

 until they have escaped from that organ. The facts on which 

 these propositions are based have been verified only in animals of 

 the lower classes; but all circumstances lead to the conclusion, 

 that they are equally true with reference to man and the higher 

 animals. 



" It is well known that at the posterior end of the abdominal 

 cavity in snails, and connected with the liver, there is a gland 

 composed of roundish sacculi, and from which a winding duct 

 extends to the uterus. In a former essay I have termed this 

 gland the racemiform organ, and expressed my suspicions that 

 it was a testicle as well as an ovary. I subsequently, however, 

 found in the organ which I termed the maternal gland, and of 

 the peculiar function of which I was then uncertain, bodies 

 which had the appearance of ova. I therefore look upon the ra- 

 cemiform organ at present as the testicle, and the maternal 

 gland as the ovary ; and for the future I shall understand the 

 former under the name of the testicle. Through the excretory 

 duct of this testicle, a thick milk-white secretion flows, which, 

 when examined by a glass capable of magnifying three hundred 

 diameters, is observed to contain long hair-like fibres, which 

 contract into serpentine folds on the addition of water, and also 

 bodies having the appearance of round discs, consisting of 

 very minute vesicles enveloped in a common external cover- 

 ing, and about 0,02 of a millimeter in diameter. I shall call 

 these bodies for the future by the name of discs, in order to 

 distinguish them from the vesicles they contain, although I 

 cannot say whether they are in all cases actually flatten- 



