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 ‘‘zstivation” 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 
1 Newly born young, Bridgnorth, Shropshire, second week of October (Pitt, 47S.) ; 
one ready to leave the nest, Skirmett, Buckinghamshire, 25th November, hence born 
say on the 4th (Cocks, 4/S.). 
2 As in the British Museum Gude fo the British Vertebrates, 1910, 5. 
3, 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. 
4 Marshall Hall, art. “Hibernation” in Todd’s Cyc. Anat. and Phys., 1839, 
764-776; see also Pocock, of. cz#.; 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. Gough’s figures are probably too high, since the average 
minimum, ze. nocturnal, temperature of April, the month of awakening, varies 
between 37:3 on the 1st and 4o-3° on the 30th. The corresponding temperatures 
occur in the autumn between the 4th (40-3°) and 15th 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. 
5 As Karl Semper puts it (Amzmal Life, 1906, 111), by reduction below the 
optimum, which optimum may, in different animals, be high or low. 
8 Centetes ecaudatus. 
