370 
SIR PETER EADE ON TORTOISES. 
ounces in each summer, and lose again a varying, but considerable 
portion of this increase during the ensuing six or seven months of 
hybernation ; but, on the whole, showing an average gain of a little 
more than one ounce in the year, — the average gain of weight per 
month in summer working out at about 6 or 7 drachms, with an 
average loss in the winter months of about 4 or 5 drachms per 
month. This last fact scarcely agrees with Cuvier’s statement that 
“ during winter . . . their loss of substance amounts almost 
to nothing.” 
It will be noted that the foregoing table shows certain variations 
in the increases and decreases of weight in the several years ; also 
that in two of the years there was but little change between the 
autumn and spring weights, — this period of stagnation occurring in 
both of the animals simultaneously. Probably several causes for 
this were at work, but I have little doubt that the variability of 
our English seasons is by far the largest factor in the case; and that 
the variations in the gainings and losings of the different summers 
and winters depend very largely upon the special character of these 
seasons. Thus, when the summer months are hot the Tortoises eat 
much more abundantly and constantly, and consequently put on 
(or rather put inside their skeletons) much more flesh than in 
colder seasons. On the contrary, a warm autumn, with a tem- 
perature not sufficiently cold to make them go early and thoroughly 
to sleep, must conduce to greater loss, or rather waste, of their 
flesh, for it is well known that these animals cease to eat many 
weeks before they finally retire to rest for the winter ; and 
necessarily during this period, especially on sunny days in which 
(even at this season) they are often moderately lively and active, 
they are doubtless breathing and consuming some of the material 
which has been stored up for winter consumption. Whilst again, 
in a very mild winter or spring they will, as is well known, 
frequently wake up from their dormancy, and of course, on each 
such occasion will make further inroads upon their reservoir of 
nutrient material. 
It is therefore pretty certain that hot summers and cold winters 
are most conducive to their rapid increase in size and weight; 
whilst of course the contrary conditions would have an exactly 
opposite result. 
Cetti says that the common Greek Tortoise seldom weighs 
