AND THE LOWER ANIMALS. 181 



vations, which, were confirmed by those of Audouin 

 and Milne Edwards, and the researches of other 

 naturalists, prove that ciliated larvae, like those of 

 infusoria, make their escape from within. In Spongilla, 

 which is a fresh-water genus, very common in the 

 neighbourhood of Paris, and which was for a long 

 while looked on as a plant, this form of reproduction 

 was observed by M. Laurent to occur during the 

 entire summer. But, in the autumn, the Spongilla' s 

 tissue becomes filled with small roundish bodies of a 

 yellowish- white colour, enclosed in a very resisting 

 envelope : these have been regarded as grains, and 

 have been termed by Laurent internal germs. They 

 survive the destruction of the surrounding parenchyma, 

 and give rise in spring to as many spongillse, which 

 in their turn produce others by the processes above 

 described. The nature of the germs to which we 

 have alluded was for a long period as undecided as 

 their origin was imperfectly known. The problem, 

 however, was eventually solved, and still more impor- 

 tant truths revealed, by M. Lieberkuhn, in a memoir 

 which received the French Academy's prize.* This 



# The subject given by the Academy in 1854 for a prize essay 

 was that of " The Eeproduction and Metamorphoses of Infusoria ;" 

 and the prize was divided between M. Lieberkiihn's work and that 

 which was presented jointly by MM. Claparede and Lachmann. 

 The latter memoir has been published, and forms the second volume 

 of the " Etudes sur les Infusoires et les Ehisopodes." It is much 

 to be desired that M. Lieberkiihn's work may be also published. 

 M. Lachmann died since that period, at a very early age, and 

 M. Claparede has briefly noticed the event, at the same time 

 expressing the sorrow of a friend who has lost the companion of 

 his studies, and the regret of a savant who sees the field of science 

 deprived of a man of genius, whose great talents promised far 

 more than his brief lifetime permitted him to accomplish. 



