180 PROCEEDINGS OP THE SOCIETY. 



and over again. He bad frequently tried the experiment, and liad found 

 that when the dried mud was moistened the rotifers constantly revived. 



Mr. Crisp, having read the paragraj)h referred to by Mr. Hardy, and 

 also a paragraph bearing upon the subject from the December number of 

 the Journal, p. 989, said that, as intimated in every number, the Society 

 did not hold themselves responsible for the views of the authors of the 

 papers noted, the object being to present a summary of them " as actually 

 published." With regard to the merits of the question, if a few minutes 

 after the moistening they found the adult forms moving about, it must be 

 obvious that they could not have come from eggs, as stated by Dr. Zacharias. 

 In 1860 a committee was appointed by the Societe de Biologic of Paris, 

 for the purpose of investigating the question. Brown- Sequard, Balbiani, 

 Berthelot, Dareste, and Eobin were members of this committee: Broca 

 had charge of summarizing the results and drawing up the report of the 

 committee. This report was published in 1860, and it remains one of 

 the most accurate statements, and the most scientifically written papers on 

 the subject. After a long series of experiments, the conclusions obtained 

 were that rotifers can be brought back to life after having remained ninety 

 days in a dry vacuum, and having been submitted to an influence of a thirty 

 minutes' sojourn in an oven heated to 100^ Celsius, that is, after having 

 been as completely desiccated as can be. These are precise and accurate 

 facts. The committee remarked, also, that the revivification of Anguillulae 

 may be effected at least twenty-eight years after desiccation ; and following 

 Leuwenhoeck's opinion, Broca believed that during desiccation vital phe- 

 nomena were much reduced, but not wholly suspended.* 



Prof. Stewart pointed out that a good deal must turn on what was 

 meant by " desiccation." It was exceedingly diflicult, under ordinary 

 circumstances, to produce a condition of complete desiccation, and it was, 

 therefore, very probable that in all cases of revivification there was sufficient 

 moisture retained to preserve life. 



Mr, A. D. Michael agreed in Prof. Stewart's view. That rotifers did 

 apparently revive after desiccation was perfectly clear, and if a full-grown 

 rotifer was revived in the manner stated, it was strange how any one could 

 be found to suppose that it had come direct from the egg. He did not see 

 any great difficulty in freely accepting the idea that the rotifers which 

 revived had not really been absolutely desiccated. It was quite likely that 

 they became covered with a coating of hardened mucus, which prevented 

 them from altogether drying up. 



Prof. Bell said that this explanation had usually been accepted as the 

 real one when this subject perennially came to the front. The most curious 

 part of Dr. Zacharias's paper, however, was that he did not in any way 

 attempt to criticize the observations of his predecessors on the facts, but 

 simply declared them to be fables, not inquiring at all into the conditions 

 under which the revivals took place, so as to ascertain whether or not they 

 were desiccated in the same sense in which his objects were when dried up 

 in a granite basin. Prof. Bell also read from Dr. Hudson's and Mr. Gosse's 

 ' Rotifera ' the pai'agraphs relating to the desiccation of rotifers (pp. 95 

 and 96), in the course of which the observations of Mr. Davis, recorded in 

 a paper read before the Society in 1873, were quoted. 



Mr. E. T. Lewis said he remembered that on the occasion when Mr. Davis 

 read his paper upon tbe subject, he brought to the meeting by way of illus- 

 tration some grapes which he had coated with gelatin, and had afterwards 

 exposed for many hours to the dry heat of a slow oven. On being cut 



* Cf. Scicucc, viii. (1886) pp. 208-9. 



