282 SEA-SIDE STUDIES. 



that of the budding of plants. To include this process and 

 the ordinary process under one expression, Auguste Comte 

 suggested the following modification of the aphorism, Omne 

 vivum ex vivo (every living being issues from a living 

 being) ; and as the idea of spontaneous generation becomes 

 every year less and less tenable, this aphorism acquires the 

 force of a law. I allude to it at starting, because, inasmuch 

 as the course of our inquiry will conduct us to the con- 

 clusion that Generation is not essentially a distinct process 

 from that of Growth in general, the idea of an ovum as the 

 necessary origin of eveiy living thing needs to be modified. 

 The first illustration we owe to Trembley, whose Memoirs 

 on the Hydra, or Fresh-water Polype, are so admirable in 

 accuracy and extent of observation, that, in spite of the 

 labours of a century, nothing of what he stated has been set 

 aside, and very little added, except what the microscope has 

 revealed. He taught us that the Polj'pe, which originally 

 comes from an egg, produces a quantity of other Polypes, 

 exactly similar to itself, by a process of "budding," after 

 the manner of a jilant. He taught us, moreover, that not 

 only is this the normal mode of multiplication, but that if 

 we lacerate the Polype, each lacerated fragment will become 

 a new Polype, which in its turn may be cut into several 

 pieces, every one of them developing into perfect Polypes. 

 Several naturalists have repeated and confirmed his experi- 

 ments. In repeating them myself I failed at first, but sub- 

 sequently succeeded, and attribute the first failure to the 

 presence of impurities in the water containing the frag- 

 ments. Mr R. Q. Couch made the curious observation. 



