iOi 



HYBERNATION. 



Animals 



which 



become 



Torpid. 



Mollusca. 



Injects. 



crevices of rocks and other hiding places, but they 

 form an operculum or lid for the mouth of the shell, 

 by which they adhere to the rock, and at the same time 

 closeup even all access to the air. If they be brought into 

 a warm temperature, and a little moisture be added, they 

 speedily revive. In the case of the Helix nemoratis, 

 the operculum falls off when the animal revives, and a 

 new one is formed when it returns again to its slum- 

 bers. The first formed opercula contain a considerable 

 portion of carbonat of lime, which is found in smaller 

 quantity in the later formed ones. If the animal has 

 revived frequently during the winter, the last formed 

 opercula consist entirely of animal matter, and are very 

 thin. The winter lid of the Helix pomalia resembles a 

 piece of card. 



All the land testacea appear to have the power of be- 

 coming torpid at pleasure, and independent of any al- 

 terations of temperature. Thus, even in midsummer, 

 if we place in a box, specimens of the Helix horlensis, 

 nemoralis or arbustorum, without food, in a day or two 

 they form for themselves a thin operculum, attach them- 

 selves to the side of the box, and remain in this dor. 

 mant state. They may be kept in this state for several 

 years. No ordinary change of temperature produces 

 any effect upon them, but they speedily revive if plun- 

 ged in water. Even in their natural haunts, they are 

 often found in this state during the summer season, 

 when there is a continued drought. With the first 

 .shower, however, they recover, and move about, and at 

 this time the concho'.cgist ought to be on the alert. 



The SPIDERS pass the winter season in a dormant 

 state, enclosed in their own web, and placed in some 

 concealed corner. Like the torpid mammalia, they 

 speedily revive when exposed to intense cold, and 

 strive to obtain a more sheltered spot. 



Many INSECTS which are destined to survive the 

 winter months, become regularly torpid by a cold ex- 

 ceeding 40. The common honey bee, in a small hive, 

 when reduced to this temperature, loses all power of 

 motion, but may be easily revived by an increase of 

 temperature. When the hive is large, there is always 

 as much heat generated, as to protect them against this 

 lethargic disposition. The house fly may always be 

 found in the winter season torpid, in some retired cor- 

 ner ; but exposure for a few -minutes to the influence of 

 a fire recalls it to activity. Even some of the lepi- 

 dopterous insects, which have been hatched too late in 

 the season to enable them to perform the business of 

 procreation, possess the faculty of becoming torpid 

 during the winter, and thus have their life prolong- 

 ed beyond the ordinary period. These insects can 

 all be preserved from becoming torpid by being pla- 

 ced in an agreeable temperature, as the following 

 experiments of Mr Cough's (Nicholson's Journal, 

 vol. xix.) abundantly testify. In speaking of the 

 Hearth Cricket, (Grylltts domesticus,} he says, " Those 

 who have attended to the manners of this familiar in- 

 sect will know that it passes the hottest part of the 

 summer in sunny situations, concealed in the crevices 

 ef walls and heaps of rubbish. It quits its summer 

 abode about the end of August, and fixes its residence 

 by the fireside of the kitchen or cottage ; where it 

 multiplies its species, and is as merry at Christmas as 

 other insects are in the dog-days." Thus do the com* 

 forts of a warm hearth afford the cricket a safe refuge, 

 not from death, but from temporary torpidity; which 

 it can support for a long time, when deprived by acci- 

 dent of artificial warmth. " I came to the knowledge of 

 this fact," he says, <> by planting a colony of these in-i 



Ar.ini.-tlt 

 T.-!iich 

 become 

 Torpid. 



sects in a kitchen, where a constant fire is kept through 

 the summer, but which is discontinued from November 

 to June, with the exception of a day, once in six or eight 

 weeks. The crickets were brought from a distance, and 

 let go in this room in the beginning of September ISOfi: 

 here they increased considerably in the course of two 

 months, but were not heard or seen after the fire 

 was removed. Their disappearance led me to conclude 

 that the cold had killed them : but in this I was mis- 

 taken ; for, a brisk fire being kept up for a whole day 

 in the winter, the warmth of it invited my colony from 

 their hiding place, but not before the evening, after 

 which they continued to skip about and chirp the 

 greater part of the following day, when they again dis- 

 appeared ; being compelled by the returning cold to 

 take refuge in their former retreats. They left the 

 chimney corner on the 28th of May 1807, after a fit of 

 very hot weather, and revisited their winter residence 

 on the 31st of August. Here they spent the summer 

 merely, and lie torpid at present (Jan. 1808) in the 

 crevices of the chimney, with the exception of those 

 days on which they are recalled to a temporary exist- 

 ence by the comforts of a fire." 



Nothing is known with regard to the hybernation Intestina. 

 of the INTESTINA, Those which inhabit the bodies of 

 torpid quadrupeds, in all probability, like them, expe- 

 rience a winter lethargy. If they remain active, they 

 must possess the faculty of resisting great alterations of 

 temperature. Among the infusory animals, numerous 

 instances of suspended animation have been observed, 

 continued not for a few months, but during the period 

 of twenty-seven years. But such instances of lethargy 

 do not belong to our present subject. Besides, they 

 have been fully discussed under the article ANIMALCULA, 

 in Vol. II. Part I. of this work. 



There is another kind of hybernation, in some re- Q u jesce& 

 spects resembling torpidity, which deserves to be taken O f animals. 

 notice of in this place, and which merits the appella- 

 tion of QUIESCENCE. The animals which observe this 

 condition, remain during the winter months in an inac- 

 tive state, requiring but little food, without however 

 experiencing the change to torpidity. 



Of these quiescent animals, the common benr(Ursus 

 arclos) is the most remarkable example. Loaded with 

 fat, he retires in the month of November to his den, 

 which he has rendered comfortable by a lining of soft 

 moss, and seldom reappears irritil the month of March 

 following. During this period he sleeps much, and 

 when awake almost constantly licks with his tongue 

 the soles of his feet, particularly those of the fore paws> 

 which are without hair, and full of small glands. From 

 this source it is supposed that he draws his nourish, 

 ment during the period of his retirement. 



This quiescence appears to differ hi its kind from 

 torpidity. This animal is always in season before he 

 retires to his winter quarters, and the female brings 

 forth her young, before the active period of the spring 

 returns, and before she comes forth from her hiding 

 place. 



The common badger is supposed to pass the winter 

 in the same manner as the bear, with which, in struc. 

 ture and habit, he is so nearly related. It is also pro- 

 bable, that many species of the genus Arvicola become 

 quiescent, particularly the amphibia or common water 

 rat, which always leaves its ordinary haunts during the 

 winter. 



It is in this state of hybernation that many of our 

 river fishes subsist at the season of the year when a sup- 



