464; Miscellaneous. 



At the meeting of the "Academie des Sciences" on the 26th Oct., 

 the following note from a M. Arnaud, who has travelled in Africa, 

 was brought before the Academy : — 



" From the inspection which I was able to make of the fly brought 

 by Mr. Oswell, at the ' Societe de Geographic,' it appeared to me 

 that it was identical with that found in the Isle of Sennar, between 

 1.5° and 11° N. latitude. Its repeated bites also kill the animals, 

 which compels the keepers of herds, especially of oxen, to leave the 

 country during the season in which it is most troublesome, that is to 

 say, from January to May ; they take refuge on the banks of the 

 Nile, where this fly very rarely occurs. 



" I have been bitten by one of these flies, and the wound resulting 

 from its bite lasted more than four months with insupportable pain, 

 which sometimes returns even now." — Comptes Rendus, Oct. 26, 

 1852, p. 603. 



Experimental Researches upon the Temperature of Reptiles, and on 

 the modifications which it undergoes under various circumstances. 

 By M. Aug. Dumeril. 



From these experiments it appears that frogs have a proper tem- 

 perature, superior to that of the water they inhabit. "When this 

 water has a temperature of 59° to 64° F., the difl^erence in their favour 

 was in no case less than 0*54° F. or more than 1*26° F. But when 

 transported into much cooler water, this difl'erence became much 

 greater; thus the temperature of the frogs remained at 47*48° F., 

 when the water in which they were immersed was only at 45*5° F. 

 The raniform Batrachia therefore display a certain power of re- 

 sistance to cold. M. Dumeril has observed that this power was 

 maintained as long as the temperature of the water was kept above 

 the freezing-point, more especially when the cooling was not sudden ; 

 but when the temperature of the surrounding medium was reduced 

 below this point, the frogs became congealed ; this, however, did not 

 always cause the death of the animals submitted to experiment. Thus 

 the author has several times been able to revivify frogs which were 

 in a complete state of rigidity, and the internal temperature of which 

 was fully 1° below the freezing-point, by placing them in contact, 

 first with melting ice, and then with water becoming gradually less 

 and less cold. 



Serpents have a proper temperature, which scarcely exceeds that of 

 the medium which they inhabit. But in order to place this fact be- 

 yond all chance of error, it is necessary only to observe these reptiles 

 at a period when neither digestion nor the change of skin is going 

 on ; the latter producing a diminution of temperature varying from 

 0*45° to 1"8° F., the operation of digestion, on the other hand, aug- 

 menting the temperature from 3*6° to 7*2° F. 



M. Dumeril has also proved that serpents ofPer less resistance to 

 increased heat than the frogs ; this is owing to the scaly covering of 

 the former, which almost entirely prevents the cutaneous evaporation 

 which takes place with so much facility through the naked skin of 

 the Batrachians. — Comptes Rendus, May 31, 1852, p. 837. 



