PROCEEDINGS OF SOCIETIES. 243 



The thanks of the Society were unanimously voted to Mr. Davis 

 for his paper. 



Mr. Slack thought that Mr. Davis's paper had been an exceedingly 

 interesting one ; but with regard to the observations upon the desicca- 

 tion of Eotifers, he believed that Mr. Davis was not the first to make 

 them.* If he-hunted over the ' Comptes Rendus,' a few years ago, 

 he would have found observations coming to the same conclusions. 

 Mr. Davis was doubtless not aware that such was the case ; and in the 

 present day, when so very much is written on every subject, it was 

 almost an impossibility to say what was new. He did not think 

 that the fact of some one else having previously made similar obser- 

 vations detracted in any way from the independent conclusions of Mr. 

 Davis. It was curious that, whilst these Callidinas seemed at first to 

 have been regarded as rarities, Mr. Davis should have found them in 

 such abundance. Callidina elegans, discovered by Ehrenberg, was 

 for some time the only species known. He believed that all the 

 known specimens had been females, and it would be very interesting 

 to discover the males, of which at present they knew nothing. The 

 number of teeth seemed to vary ; Ehrenberg said that Callidina elegans 

 had two jaws, and a number of very fine teeth, whilst another species 

 was described as having only two teeth in each jaw. 



Mr. Wenham said that revivification was not confined to Rotifers, 

 although common amongst them. He remembered when in the lower 

 part of Egypt, near the Pyramids, finding some snails upon the 

 ground which seemed quite dried up, so much so that they cut with a 

 knife like a piece of dry cheese-paring. They were found in a place 

 where the heat of the sun was very great, the stones they were on 

 being almost too hot to bear the hand on. He took some of them 

 down with him to the boat, and put them in a plate with some mois- 

 ture and some slices of cucumber, when he found that in a short time 

 one of them filled out with the water, put forth his horns, and began 

 to feed on the cucumber. He mentioned the circumstance of finding 

 them in such a place where there was very little moisture or vegeta- 

 tion, and rain scarcely ever fell, and Dr. Carpenter thought they must 

 have been brought there by the wind from some more fertile part. 

 In reply to a question from the President, Mr. Wenham said they 

 were a species of Planorbis. 



Mr. Davis said that Mr. Slack's remarks as to the species of Calli- 

 dina were quite correct, but he took exception to the statement that 

 some one had previously shown what he had himself just demon- 

 strated. No doubt, it had been said that Rotifers would not revive 

 after being actually dried up, but it had never been shown that those 

 which did revive had not been actually dry. 



Mr. Slack said the subject had been investigated before, and the 

 same conclusions had been arrived at ; he would endeavour to find 

 the article to which he had referred. 



Mr. Davis said he had proved that, under certain circumstances, 

 the air-pump was not such a perfect desiccator as was generally 

 believed, and ho had also shown how it was that these Callidinse did 

 * See Mr. Slack's letter, p. 241. 



