BY H. S. HALCKO WAUDLAW. 253 



12*2°C., respectively (Hunt, loc. ciL), may account for the fact in 

 part, but, apparently, not altogether, as an examination of the 

 diagrams and tables will show that the animals were sometimes 

 awake and active at temperatures lower than those at which 

 they were, at other times, torpid. Temperature seems, therefore, 

 not to be the only factor concerned in the bringing on and main- 

 tenance of hibernation, as has also be^*n supposed in the case of 

 European hibernants. 



With regard to the rate at which the animals enter into or 

 emerge from a state of hibernation, no very detailed information 

 can be gained from the tables and diagrams, as the temperatures 

 were not observed at frequent enough intervals. The large falls 

 of temperature, indicating the entrance of an animal into a state 

 of hibernation, generally occurred between an afternoon-observa- 

 tion of the temperature and the succeeding morning-observation. 

 Falls of temperature of as much as 16''-17° occurred in this period 

 of twenty hours, as in the case of Echidna No. 6, on June 16th- 

 17th, and of Echidna No. 7 on June 3rd-4th. Between the 

 morning- and afternoon-observations, a period of about four 

 hours, comparatively sudden rises of temperature occurred as the 

 animals awoke from hibernation. For example, in the case of 

 Echidna No. 6, on June 15th, a rise of 12*0" occurred in the above 

 interval of time; and, in the case of Echidna No. 7, a rise of 

 13'8" occurred on June 5th, in the same period. 



delation between temperature of Echidna and temper at,ure of 

 air. — Let us consider now the temperature of Echidna during 

 the periods in which no hibernation occurred, Autumn, Spring, 

 and Summer. Tt will be seen that, during these periods of 

 observation, firstly, the morning-temperature of the animals was, 

 with only one or two exceptions, lower than the afternoon- 

 temperature; and, secondly, that, although the morning- and 

 afternoon-temperatures each showed variations considerably 

 greater than are met with in the case of human beings, yet 

 these variations seem to have occurred about a sort of mean 

 value; and we may therefore speak of these temperatures as 

 having certain average or mean values, always bearing in mind 

 the very doubtful significance of any average or mean figure as 



