THE SEMEN. 189 



much more regularly present in the seminal animalcules of 

 the bat, in which they occur as pointed spines. The same 

 observer has, moreover, noticed upon one or two occasions 

 the caudal end of the body to be double, bifid, or forked, 

 and once too the body appeared to be double, as in a bi- 

 cephalous monster. * 



The above comprise all the particulars which have hitherto 

 been promulgated in reference to the organization of the 

 spermatozoa ; scarcely any one of them has however been 

 sufficiently established : we are therefore not authorised to 

 receive them as proved, and to build any reasoning upon 

 them : the most which we are warranted in deducing from 

 them amounts to this, that traces of organization have been 

 discovered in the spermatozoa, the precise nature and extent 

 of which have not as yet been satisfactorily determined. 



Notwithstanding his observations given above, Wagner f 

 states that he has been utterly unable, after varied, repeated, 

 and long continued examination, to discover true internal 

 organs in the spermatozoa. Siebold J has also been equally 

 unsuccessful in his endeavours to detect such, as also Henle 

 and Koelleker. 



The determination of the fact that the spermatozoa are 

 possessed of even the smallest amount of organization, would 

 involve their classification in the animal kingdom, and the 

 description of the different forms which occur as so many 

 distinct species. 



The view of the animal nature of the spermatozoa would 

 appear to gather strength, and to admit almost of positive 

 demonstration, by reference to their very remarkable motions. 



MOTIONS OF THE SPERMATOZOA. 



It is impossible that anything can convey a more just idea 

 of life than the spectacle of a drop of the seminal fluid in 

 which the spermatozoa are in active and ceaseleps motion. 



* Elements of Special Physiology, pp. 10. 16. f Loc. cit. p. 17. 

 | Siebold in Weigman'a Arcliiv. 1838. 

 Anatomic Generale, t. vii. p. 531. 



