JOURNAL OF CONCHOLOGY. 32 1 



ON THE ACTION OF THE HEART IN THE HELICID^ 

 DURING HIBERNATION. 



By CHARLES ASHFORD. 



Cold-blooded animals possess very little proper heat, that is 

 to say the internal temperature of their bodies is, in all seasons, 

 nearly the same as that of the medium in which they live. What 

 difference exists has not been satisfactorily determined, but it 

 appears not to exceed two or three degrees and does not concern 

 us on the present occasion. The rate of pulsation of the heart of 

 our Land Mollusks, during the active part of their existence, has 

 long been known to be intimately related to the external tem- 

 perature, though it cannot be said in a strictly mathematical 

 sense to vary as the temperature. It is accelerated with a rise 

 and reduced with a fall of the thermometer. The coolness of 

 autumn, coupled with the less accessibility of food induces the long 

 torpor in which most t)f them pass the winter months. 



As to the amount of functional activity existing during 

 hibernation authors are not agreed. A few maintain that all the 

 functions are in absolute abeyance. Several allow that a very 

 imperfect respiration is kept up. But most agree in stating, either 

 directly or by implication, that the heart ceases to beat when the 

 animal resigns itself to its winter sleep, and does not resume 

 activity till the following spring. Lister, quoting Peier, is almost 

 alone in saymg that ''in spite of the state of inertness the beating 

 of the heart, even in the coldest weather, affords a manifest 

 indication of life" (Exer. Anat., p. 164). Unfortunately his 

 opinion was based on the results of direct vivisection or upon 

 appearances after the shell of the animal had been removed, and 

 he does not seem to have suspected that the local irritation 



