110 BRITISH &HIDES. 



prefer to acknowledge his ignorance, rather than give 

 an opinion in such a labyrinth." "S' il fallait une expli- 

 cation a toute force, j'admettrais que la generation se 

 fait ici comme chez quelques Entozoaires, par indivi- 

 dualization d'un tissue precedemment organise." 



He says that the generation on that account is not 

 spontaneous, for such a generation ought to be the 

 product of an organised being, "de toutes pieces," when 

 the inorganic elements unite to produce an animal or 

 plant. " This has never taken place, and is impos- 

 sible." Again he continues : " La generation equi- 

 voque " is that when the tissues previously organised 

 by a being provided with life individualise themselves, 

 that is to say, separate themselves from the common 

 mass, and still participate in the dynamic state of the 

 mass after this separation for its own benefit. Thus 

 it is that a tissue produces an Entozoon. It is a 

 continued life. 



He continues : " But suppose that the life has a 

 sufficient energy to impress itself on the tissue which 

 individualises itself .... in such a case you have 

 the generation of the Aphis. This energy is lost 

 at the end of certain generations; and then a new 

 impulse becomes necessary ; and this impulse comes 

 from the male."*" 



It is obvious that such a process amounts to a 

 non-sexual " budding," now so commonly known to 

 prevail amongst the lower animals. 



In another place Morren assigns the origin of the 

 non-sexual viviparous Aphis to a body — " d'ocuf forme 

 de globules reunis, et sans enveloppe apercevable." 



M. Balbiani remarks, it will be more rational to 

 compare this body either to a true ovum or else to a 

 ^•(•l'lniiiniivc sac, after the example of other naturalists. 



Morphologically ov:i may be regarded as buds, with 



this special difference that the latter arc incapable of 



fertilisation. If this difference did not exist, some, 



like Leuckart, might assert that in certain kinds of 



* Ch. Morren, " Puceron du pecher," ' Ann. des Sc Nat.,' p. 65, 1836. 



