the Seminal Fluid of Animals. 



have very little doubt that Treviranus will ultimately succeed 

 in establishing the very curious and remarkable analogy which 

 he has been the first to observe and investigate. Mi 



" Although the beings termed seminal animalcules, have been 

 frequently made the subject of observation for the last hundred 

 and fifty years, the question as to their peculiar nature has ne- 

 ver yet been satisfactorily answered. Since the abandonment of 

 the opinions of Leeuwenhoek, who maintained that they were 

 the germs of the embryos, they have been generally looked upon 

 as belonging to that class of animals which are generated in all 

 infusions of organized substances. To the latter, it is true, they 

 bear an external resemblance. But even in the case of infusory 

 animalcules, our knowledge of all the individuals of this deno- 

 mination is not sufficiently accurate to authorize us to place the 

 whole in one and the same class. Ehrenberg discovered in many 

 of these animals a more complicated internal structure than had 

 been previously assigned to them : in many, for instance, he 

 found a real mouth and intestinal canal. But many of them 

 appeared, even under the best magnifying glasses, not more per- 

 fect in their interior than various hydatids and other secondary 

 products of the formative organic powers. Among the latter 

 products, the most noted are generally observed as excrescences 

 from solid parts, and without any manifestations of motion. 

 This, however, is not always the case. In man and other ani- 

 mals, hydatids are occasionally generated, which contain only a 

 watery fluid enclosed in a vesicular membrane, and which have 

 no connexion either with each other, or with the walls of the ca- 

 vity in which they lie. Similar formations may he also very 

 naturally produced in fluids situated in the interior or on the 

 surface of organized bodies, may grow by the absorption of cer- 

 tain constituents of these fluids, and in consequence of the at- 

 traction they have towards some, and the repulsion towards 

 other particles of matter, may be capable of exhibiting motions. 

 Beings of this description cannot be ranged in the same division 

 with the true infusory animalcule?. Those which are met with 

 in animal or vegetable secretions may form important constitu- 

 ents of the same, and contain a substance which may have a 

 principal share in the functions of these fluids. Among beings 

 of this kind we may, perhaps, place the seminal animalcula. 



