HYDEA. 177 



soon after he had the satisfaction of hearing from him that 

 they had arrived alive ; that he had examined them, and 

 hesitated not to rank them among animals ; and this put an 

 end to M. Trembley's doubts. 



Though he ceased to doubt as to their animal nature, 

 he ceased not to carry on his observations, particularly as 

 to their mode of multiplication. He thought he ascertained 

 that this is sometimes by eggs, which, when emitted from 

 the body of the polype in autumn, sink into the mud, in 

 which they lie during the winter, to be transformed into 

 polypes when the vernal sun shines forth on them. He 

 observed also, on several occasions, that a polype became 

 divided into two, that at first there was a stricture about 

 the middle of the body, that the division took place at this 

 stricture, and that, before separating, the tail part had 

 acquired tentacula, and was thus prepared to support itself 

 as independent. Ear more frequently they multiplied by 

 buds, as we have already said ; and he gives a particular 

 account of his observations as to this mode of multiplication. 

 At first there was a little gemmule on the cylindrical body 

 of the green polype, chiefly observable by its darker colour. 

 In a day or tw^o it had projected from the parent polype 

 about a line; in a few days, when it had still more increased 



N 



