Chap. XIII.] EOTIFERA AND PASTE-EELS. 



487 



But although these different species may die and be re- 

 suscitated several times in succession, this power has its 

 limits, and each successive experiment generally proves fatal 

 to one or more individuals. Spallanzani, in his experiments 

 on the Rotifera, did not find that any survived after the six- 

 teenth alternation of desiccation and damping, but paste-eels 

 bore seventeen of these vicissitudes. 



Spallanzani, after thoroughly drying sand rich in Rotifera, 

 kept it for more than three years, moistening portions taken 

 from it every five or six months. Baker went further still 

 in his experiments on paste- eels, for he kept the paste from 

 which they had been taken, without moistening it in any 

 way, for twenty-seven years, and at the end of that time the 

 eels revived on being immersed in a drop of water. If they 

 had exhausted their lives all at once and without these inter- 

 missions, these Rotifera and paste-eels would not have lived 

 beyond sixteen or eighteen consecutive days. 



To remove all doubt as to the complete desiccation of the 

 animalcules experimented on by Spallanzani and Baker, M. 

 Doyere has published, in the Annales des Sciences Naturales 

 for 1842, the results of his own observation, in cases in 

 which the mosses containing the insects were dried under the 

 receiver of an air-pump and left there for a week ; after which 

 they were placed in a stove heated to 267° Fahr., and yet, 

 when again immersed in water, a number of the Rotifera be- 

 came as lively as ever. 



Further particulars of these experiments will be found in 

 the Appendix to the Rambles of a Naturalist, &c, by M. 

 Quartrefage. 



II 4 



