[CAMERON] HISTORY OF THE FROG 19 



at a temperature of 19°C. On January 8th the cover was raised and 

 the frog remained motionless in the resting attitude. On being 

 stimulated with a glass rod it failed to react at first, but within a 

 minute it became aroused from its lethargy, raised its head above 

 water, came out of the dish and then swam vigorously away. The 

 next day it was perfectly normal and very active. The winter sub- 

 mergence of the frog {R. temporarid) , as observed under laboratory 

 conditions, was described by G. Newport in 1851." 



Professor Philip Cox, of the Department of Biology of the 

 University of New Brunswick, Fredericton, has very kindly sent me 

 the following account of his observations: 



"I have some rare advantages as regards a water supply at the 

 ordinary winter temperature of surface spring water. 



"The aquaria, two in number, are in my lecture room on table 

 supports of the usual height. They are of glass and metal .... 

 about 32" X 18" x 16" in dimensions. The infîow and outflow are 

 by separate pipes, and the supply is from a spring on the ascending 

 ground, just behind the Arts building, and covered by a low shed. 

 These tanks were installed to keep fish, clams, crayfish, and frogs for 

 biological study and have admirably served the purpose. 



"The frogs are principally R. virescens, with an odd R. clamitans, 

 and are collected about September 20th each year. They are put 

 into the tanks which remain filled with water to within three inches 

 of the top (cover). 



"At first I put in a few bits of board, which floated, and on 

 which the frogs were inclined to sit day and night, taking an occasional 

 plunge and returning to their forms; but as the temperature of the 

 room was seldom below 60°F., they persisted in sitting on their 

 perches until far into the winter and as a result fell off in condition. 

 A few very large ones would, however, dive to the bottom and remain 

 among the coarse algae and pebbles, seldom coming to the surface. 

 As the winter advanced they were joined by more from the surface 

 until about the middle of January few were left at the surface. The 

 R. clamitans were inclined to hang to the surface the longest. 



"Two years ago I fitted shelves just far enough below the surface 

 to admit of the frogs resting there with their eyes and tips of the 

 snouts out of water. This resulted in helping to keep them in better 

 flesh and it was observed that the circulation of the blood was stronger 

 and more rapid than under the former conditions. These perches, 

 however, were later abandoned for forms on the bottom, where, if not 

 disturbed, they remained motionless for long periods. As the light 

 (the tanks are near a big window) must exercise a disturbing influence or 



