324 ashford: the action of the heart in the helicid^. 



The error in each case, however, probably does not exceed unity. 

 On three occasions, not recorded, no movement of the heart was 

 perceptible, but whether this was the result of absolute cessation 

 or from concealment of the organ, I cannot say. 



With regard to the main point — the action or non-action of 

 the heart during hibernation — these numbers speak for them- 

 selves, so far as H. hortensis is concerned. But I defer a few 

 remarks till I have given the observations on Zonites cellarius, 

 which are these: — 



Temperature... 43, 42, 33, 26, 44, 38, 37, 27, 38, 43, 41, 31, 30, 26, 43, 52. 

 Pulse 13,13, 8, 4,12,11, 9, 5,13,14,10, 8, 9, 5, I3>2i. 



On every occasion throughout the three months the heart of 

 this Zonites was in distinct action. 



We see then, so far as the enquiry has extended, clear 

 evidence of the continuity of the circulation during the winter as 

 well as the summer life of these animals so long as the ther- 

 mometer does not fall below 26° — 28° F. There is no sudden 

 dislocation when the period of hibernation is entered upon, but 

 an unceasing flow of the vital fluid, more and more sluggish as 

 the temperature falls, but fluctuating with the varying temperature 

 in obedience to the same law as obtains during the active feeding 

 season. It would appear, however, that the limit of endurance is 

 nearly reached when the thermometer shows a few degrees of frost. 

 Unfortunately (for my purpose), the winter of 1881 — 2 was 

 comparatively mild and no opportunity presented of testing the 

 case at say ro or 12 degrees of frost. At such a point the animal 

 fluids perhaps congeal, but it would be interesting to discover 

 whether cessation of circulation takes place before this catastrophe 

 or is occasioned by it. 



J.C, iii., July, 1882 



