Physiology of Helix Pomatia. 90 



immediately after the formation of the operculum, proving that 

 the secretion has not gone on during hibernation. One of the ani- 

 mals had suffered the removal of the large tentacula in the month 

 of June, Avhich had been partially reproduced at the period of hi- 

 bernation, and in the next spring the reproduction was found not 

 to have advanced in the slightest degree during that period. Re- 

 specting the functions of nutrition and absorption the author 

 arrives at a similar conclusion. 



§ 15. It is therefore proved that during the winter, that is to 

 say, for five, six, seven, or even eight, or nine months, accord- 

 ing to the climate and season, these animals exist without motion, 

 animal heat, nutrition, respiration, circulation, &c. in a word, 

 deprived of all their animal, organic, and' generative functions. 

 This obscure existence cannot in fact be properly called life, but 

 rather a simple aptitude for life, on the return of the genial tem- 

 perature of spring. 



§ 16. In our climate it is about the beginning of April, soon 

 after the song of the cuckoo begins, and the swallows appear, that 

 the snails leave their torpid state, varying a little however accord- 

 ing to the season. The mode by which their escape from confine- 

 ment is effected is simple and easily comprehended. The air 

 which is contained in the different cells, and which had been ex- 

 pired on the animal withdrawing itself farth(;r and farther into 

 the shell after the formation of the operculum, is again inspired, 

 arid each separate membranous partition broken by the pressure of 

 the hinder part of the foot projected through the mantle. When 

 it arrives at the calcareous operculum, the animal, making a last 

 effort, bursts and detaches its most obtuse angle. Then insinuat- 

 ing by little and little the edge of the foot between the shell and 

 the operculum, it forces the latter off or breaks it away. The 

 animal then comes forth, walks, and immediately begins feeding 

 with an appetite excited doubtless by an abstinerce of six or 

 seven months.* 



* It cannot be supposed that the long abstinence of the animal has any effect 

 in exciting its appetite, when it is recollected that di'ring the whole of its hi- 

 bernation, it is in a state of temporary death, and nnithei- secretien, the pro- 

 duction of animal heat, noj- any other watting function t;oing on. B. 



e2 



