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THE AMEBIC AX NATURALIST 



[Vol.L 



Hahn 58 (1914) concludes that the torpid condition is not 

 dependent npon cold weather, although his thirteen-lined 

 ground squirrel usually hibernated with each cold spell 

 and woke up with the return of warm weather. Experi- 

 mentally it was early shown that cold will not induce 

 typical lethargy. Thus Buff on 4 (1749) in the case of the 

 hedgehog, Daubenton 59 in the hamster, Hunter 9 (1775) 

 in the dormouse, Mangili 19 (1807) and Bossi 6e> in the mar- 

 mot, Horvath 56 in the spermophile and hedgehog and 

 Mares 42 (1892) in the spermophile, have failed to induce 

 true hibernation by exposure of the animal to low temper- 

 atures. Saissy 35 (1808) is supposed to have produced 

 winter-sleep by continued cold and confined air; but like 

 some other reported cases of artificially produced torpor, 

 it is not clear that the experimentally produced state was 

 the same as true hibernation. Sacc 61 (1858) after eight 

 years of observation on the marmot could see no relation- 

 ship between the condition of the atmosphere and winter- 

 sleep. Mills 62 (1892) found that while bats could be 

 worked like a machine by varying the temperature, mar- 

 mots, on the contrary, showed a surprising indifference 

 to the surrounding temperature. Berthold 03 (1837) 

 claims that dormice became dormant in a room kept warm 

 (16° C.) all winter, though torpidity was delayed two 

 months. Merzbacher 40 (1904) mentions similar experi- 

 ences of his own with a bat, as well as several other com- 

 parable cases. Mangili 19 (1818) saw a dormouse fall into 

 lethargy in the month of June and not wake up till the 

 middle of July. Forel 52 (1887) records that two dormice 

 which remained awake and active all winter, became tor- 

 pid in May and remained in this condition till August in 

 spite of the great heat. Mares 42 (1892) found that some 

 spermophiles and hamsters may hibernate in September 

 at 16° C. while others remain awake all winter although 

 the thermometer falls below zero. Hence he concluded 

 that cold does not cause winter-sleep. Valentine 64 (1857), 

 Horvath 56 (1881) and Quincke 38 (1882) have observed 

 marmots become dormant during the summer. Hence 



