the Seminal Fluid of Animals. 345 



employed by Treviranus, Again, the two former regard the 

 linear or hair-shaped bodies alone as the true seminal animalcu- 

 la ; while Treviranus looks upon them as probably nothing more 

 than mere peduncles or fibres of attachment for the vesicles, 

 which contain the most important and essential constituent of 

 the seminal fluid. 



The seminal animalcula were first observed in the early part 

 of the year 1677, by Louis Hamme, a German student, who 

 was at that time on a visit with Leeuwenhoek, to whom he com- 

 municated his discovery. This indefatigable observer imme- 

 diately occupied himself with the subject, and in the month of 

 November 1677, transmitted to London an account of the disco- 

 very, with a description of the spermatozoa, in a letter to Viscount 

 Bruncker, which was afterwards published in the 142d No. of the 

 Philosophical Transactions. This communication was received 

 with great applause ; and the facts were shewn to Charles II. and 

 many scientific individuals. They were subsequently examined 

 and admitted by Hartsoeker (who also claimed the discovery), 

 Asche, Huygens, Spallanzani, Haller, Bonnet, Morgagni, and 

 several others ; and engrossed a considerable share of the atten- 

 tion of physiologists about the latter end of the 17th century. 

 These investigations subsequently fell into neglect ; but appear 

 about to be revived again in Germany, and in the hands of such 

 men as Treviranus, Ehrenberg, and Purkinje, may ultimately 

 tend to throw some light on one of the most obscure and interest- 

 ing subjects in physiology. 



Further Observations on the Unity of Structure in the Animal 

 Kingdom, and on Congenital Anomalies, including " Her- 

 maphrodites ;" with some Remarks on Embryology, as faci- 

 litating Animal Nomenclature, Classification, and the study 

 of Comparative Anatomy. By MARTIN BARRY, M. D., 

 F.R.S.E., M. W. S. Communicated by the Author. 



IN a former memoir on this subject,* certain conclusions were 

 arrived at, which, to save reference, it may be proper to re- 

 peat, viz. 



\stly, That a heterogeneous or special structure arises only out of one more 

 homogeneous or general, and this by a gradual change. 2rf/y, That the man- 



* See the last Number of this Journal, p. 141. 



