ZOOLOGY. 353 



the natural size, form, and appearance of the specimen, by coating it -with 

 gutta-percha from a solution. The specimen which was exhibited had the 

 appearance of the purest papier-mache preparation, and possessed the advan- 

 tages of presenting not only the natural color of the tissues, but also the re- 

 lations of the muscles, nerves, vessels, etc. . 



For detailed account, see Proceed. Acad. Nat. Sciences, Phil 



ON THE DESTRUCTION OF MARINE ANIMALS BY CHANGES IN 



TEMPERATURE. 



At a meeting of the Royal Society of Edinburgh, Hugh Miller called atten- 

 tion to the extensive destruction effected last winter of the shell- fish on the 

 coast of Scotland, by a severe frost coincident at new-moon with a stream- 

 tide. In some places the beaches were covered with tens of thousands, chiefly 

 of two species, a Solen. or razor-fish, and a Mactra. Other species of shells, 

 equally abundant and exposed to the cold, did not appear to suffer at least 

 to any great extent. This wholesale destruction by a frost, a few degrees 

 more intense than is common, strikingly shows, how simply by slight changes 

 of climate, induced by physical causes, whole races of animals may become 

 extinct. 



Observations on the Preservation of Marine Animals in an " Aquarium.-' 1 

 In a discussion on the above subject before the British Association, Mr. "War- 

 rington stated that temperatures below 45 destroyed many forms of animal 

 life, especially Crustacea, while a temperature exceeding 60 Fahrenheit, was 

 destructive of both animal and vegetable life. Too great exposure to light 

 was also destructive of creatures kept in the Aquarium. 



Dr. Fleming related, in connection with the subject of keeping animals in 

 sea-water, that he had in his possession an Actinia, originally captured by 

 Sir John Daly ell, that had now been in captivity twenty-eight years. 



ON THE ROOSTING OF BIRDS. 



At a recent meeting of the Boston Society of Natural History, Professor J. 

 Wyman referred to the commonly received explanation of the manner in 

 which birds retain their position in roosting. Bovelli attributed the bending 

 of the toes to the mechanical action of the salient angles, over which the 

 flexor tendons passed. Professor "Wyman thought this gave, at best, but a 

 partial explanation ; for, while roosting, the body requires to be accurately 

 balanced, since, at every act of respiration, the center of gravity must neces- 

 sarily be changed, and the requisite adaptations can be effected by muscular 

 action only. In those waders which roost on one leg, the balancing of the 

 body becomes a matter of still greater nicety ; and in these, too, the tibia is 

 not flexed upon the tarsus, therefore the tension of the tendons, as stated by 

 Bovelli, would not be effectually produced. In bending the leg of a dead 

 bird, the toes do not adapt themselves to the surfaces on which they rest. He 

 ihought the explanation must be found in reflex muscular action, an explana- 

 tion which had been suggested to him by Dr. S. Cabot. 



