HEAT UPON LIVING MATTER. 151 
the organism which is born from it. The life of the 
egg is “trés foible’—“sa vie est moins vie.” And 
then Spallanzani asks whether the fact of this life of 
the embryo within the egg being “so small and so 
feeble’”’—being “a life which deserves so little the 
name of life”—may not be the reason that eggs are 
able to bear the influence of heat better than the 
developed organisms whose existence is more active 
and complex? He believes this to be the principal 
reason of the increased power of resisting heat dis- 
played by eggs, and in support of it calls attention 
to the fact that many animals (as well as plants), when 
the rate of their vital phenomena is lowered, during 
winter sleep, are much better able to withstand many 
injurious external influences than when they are dis- 
playing to the full all the manifestations which 
constitute their ‘life. Animals—such as frogs and 
salamanders, for instance—resist the effects of injuries 
better, when they have been incurred during the be- 
numbing cold of winter than at periods of the year 
when organisms like these are full of life and activity. 
A similar difference obtains between the degree 
and complexity of the life of seeds as compared with 
that of plants, and this difference may in part simi- 
larly explain the superior power of resistance to heat 
shown by seeds. Here, also, amongst plants, we find 
that ability to withstand hurtful influences generally 
