THE DORMOUSE OR SLEEPER 369 



until the first week of November.^ These would require their 

 mother's attention so long as possibly to delay her own hiber- 

 nation ; hence it has been thought ^ that the members of these 

 late broods always perish. The young certainly become 

 lethargic more tardily than adults, and in captivity they often 

 seem to be unable to put up fat, and may die in an emaciated 

 condition without attempting to hibernate.^ They must find 

 the conditions of life harder than the earlier litters, but 

 Mr Steele Elliott has kept them successfully through the 

 winter. 



Hibernation is more rigidly fixed in the routine of life 

 in dormice than in hedgehogs. The influence of tempera- 

 ture* is shown, however, by their greater activity when kept 

 warm in confinement, so that cold is evidently a predisposing 

 cause, a stimulus which, as it were, starts the process.^ It may 

 not be more than this, since the corresponding condition known 

 as " cestivation " manifests itself in the Tenrec^ of Madagascar 

 under precisely opposite conditions, namely, in the hot season. 



The processes concerned are evidently very complicated • 

 and incapable of explanation under any single heading. It is 



' Newly born young, Bridgnorth, Shropshire, second week of October (Pitt, MS.) ; 

 one ready to leave the nest, Skirmett, Buckinghamshire, 25th November, hence born 

 say on the 4th (Cocks, MS.). 



^ As in the British Museum Guide to the British Vertebrates, 1910, 5. 



' R. F. Tomes, in Bell, ed. 2, 284. In one case a member of a spring brood 

 became torpid six weeks later than an adult. 



* Marshall Hall, art. "Hibernation" in Todd's Cyc. Anat. and Phys., 1839, 

 764-776; see also Pocock, op. cit.; and bibliography in Phil. Trans. Roy. Soc, 

 London, 1832. In 1792 a Mr Gough informed William Bingley that two captive 

 dormice became inactive whenever the thermometer dropped to 42° F., resuming 

 their activity at 47° F. Cough's figures are probably too high, since the average 

 minimum, i.e. nocturnal, temperature of April, the month of awakening, varies 

 between 37-3° on the ist and 40-3° on the 30th. The corresponding temperatures 

 occur in the autumn between the 4th (40-3°) and isth November (37-4°)' For these 

 figures, compiled from the records for the sixty-five years 1841 to 1905 at Greenwich, 

 I am indebted to W. W. Bryant, of the Royal Observatory. They must be taken as 

 applying only roughly to other districts, and of course vary considerably from year to 

 year. In 1793 Gough fed another dormouse well from April throughout the succeed- 

 ing summer and winter, with the result that, although without artificial heat, it 

 remained in good health and high condition, and during that winter never slept for 

 more than forty-eight hours consecutively, and that but seldom ; it was also active in 

 the winter of 1794-5. 



' As Karl Semper puts it {Animal Life, 1906, iii), by reduction below the 

 optimum, which optimum may, in different animals, be high or low. 



° Ce nteies ecaudatus . 



