EFFECTS OF FEEEZING. 113 



and when fully grown ; it is well known that salmon's eggs, 

 with the embiyo in them, are conveyed in ice even to America 

 and Australia ; other animals, again, can bear such cold only 

 in the egg state. Many insects perish in. the winter, while their 

 eggs siuviTe, and the embryo within the egg of many insects 

 cannot be frozen even at an extremely low temperature. The 

 so-called winter eggs of many of the lower crustaceans — 

 DaphnidoR for instance — and the germs or statoblasts of Bryozoa, 

 or of the fresh-water sponges, resist any degree of cold, while 

 the fully grown individuals regularly perish itt the autumn, 

 apparently from cold. So far as I know, no explanation has 

 yet been given, or even sought for in the right way, of the 

 fact that the soft contents of so minute a body as the egg or 

 germ of an invertebrate animal cannot be frozen so long as 

 it remains enclosed in its fu'm but always extremely delicate 

 capsule. 



With regard to the capability manifested by many animals, 

 or even certain separate organs, of enduring to be frozen up 

 without having lost their vital powers in the smallest degree after 

 they are thawed, many observations have been recorded, but 

 hardly any, if any, thorough and complete series of experiments. 

 The statements that have been made are often nothing short of 

 astounding. Thus it has been said that frogs and toads do not 

 die even when so completely frozen that their skin, muscles, and 

 bones can be broken up into fragments. The extremely delicate 

 marine Naked Mollusca are said, like many other MoUusoa, to 

 endure freezing La ice without injury, and excised portions, as 

 the heart, muscles, or nerves, to undergo the same treatment 

 without losing their functional powers. But, on the other side, 

 Pouchet declares, on the ground of various experiments, that 

 actual freezing infallibly kills separate members, and perfect 

 individuals too ; for according to him the corpuscles of the 

 blood are in the fii'st instance destroyed by freezing, and these 

 dead elements act as a poison after the individual is thawed, 

 killing the animals, or, as the case may be, the organs. This 

 view, if not actually conti-adicted by Horvath's researches, is 

 rendered improbable, to say the least ; for from them we learn 

 that a frog whose legs have bean killed by freezing lives on all 



