Reproduction in the Hydra viridis, t281 



'Zoologists who travel over these distant countries will do well 

 to sojourn on the borders of the lake Feia, of the lake Padre 

 Aranda, or of the Rio des Piloes, in order to ascertain the 

 perfect truth — to learn precisely what the minhocao is ; or 

 whether, notwithstanding the testimony of so many persons, 

 even of the most enlightened men, its existence should be, 

 which is not very likely, rejected as fabulous. — {Comptes 

 Hendus^ Dec. 28, 1846.) 



On the Co-existence of Ovigerous and Spermatic Capsules on 

 the same individuals of the Hydra viridis. By Allen 

 Thomson, M.D., F.R.S.E., Professor of Physiology in 

 the University of Edinburgh.* Communicated by the 

 Author. 



The object of the following communication is to lay before 

 the Royal Society a few observations which I made in the 

 months of October, November, and December of 1845, upon 

 the occasional reproduction of the common green polype of 

 Fresh water (hydra viridis) by means of fecundated ova ; and 

 in particular upon the existence of spermatic and ovigerous 

 capsules in the same individual. 



I may be permitted to explain, in reference to these obser- 

 vations, that at the time they were made, I conceived them 

 to be new, in so far as the bisexual condition of single indivi- 

 duals of the polype is concerned ; but 1 have since found that 

 I have been anticipated by other observers in the announce- 

 ment of the fact ; and I have therefore to request the Society 

 to receive this communication rather as confirmatory and illus- 

 trative of the circumstances to which it refers, than as intended 

 to bring forward any new discovery. 



I have further to express my regret that accidental circum- 

 stances, and the only occasional occurrence of the pheno- 

 mena, should have prevented me from making the observa- 

 tions as complete as might have been desirable. 



* Commuuicated and read to the Royd Sociity of Edinburgh, March 1847. 



