170 



CRICHTONITE CRICKET. 



45, and at the diaphragm 48A. When the tempera- 

 ture of the atmosphere was at 20, the heat of the 

 animal in the cavity of the abdomen, where an inci- 

 sion was made, was reduced so )o\v as JJO". The same 

 animal, when exposed to the cold atmosphere of 'JC, 

 for two days, had its heat at the rectum elevated to 

 93, the wound in the abdomen being so much dimi- 

 nished in size as not to admit the thermometer. At 

 this time, however, it was lively and active, and the 

 bed in which it lay felt warm. As the heat of this 

 animal descended to 30, when in its natural state of 

 torpidity, and when there was no necessity for action, 

 the increased temperature may in part be ascribed to 

 the wound, which called forth the powers of the 

 animal to repair an injury, which could not be done 

 below its standard temperature. 



Many similar experiments have been made, and the 

 result of them all is, that the winter temperature of 

 the hamster does not warrant the supposition that, 

 however still it may be during the winter, it ever ac- 

 tually hybernates. For, contrary to what is the case 

 with animals which do hybernate, the temperature of 

 the hamster is as high at mid-winter, as that of the 

 average of animals during the summer, and, indeed, 

 higher ; and, though the fact has not been sufficiently 

 examined, it agrees with analogy that, with equal 

 action, any animal should be warmer in winter than in 

 summer; although the temperature of every animal 

 will, of course, sink when that animal remains inactive. 



That the temperature of this animal should have 

 been found a few degrees higher in March and April, 

 than it was earlier in the season, is no proof of com- 

 ing from a state of dormancy, though it is a proof of 

 some action ; but the probability is, that this increase 

 had a physiological cause, and was connected with 

 the breeding of the animal. This part of the subject 

 is however obscure, and we want a good deal of care- 

 ful observation, before we can come to any just con- 

 clusion on the very important subject of the seasonal 

 changes of temperature to which animals are subject, 

 both on account of their own nature, and of the cir- 

 cumstances under which they are placed. 



Throughout the wide range of territory which it 

 inhabits, the hamster is subject to very considerable 

 changes of colour ; and, it should seem that, as it 

 habits more northerly, it fades more into a white 

 colour, and this, again, is in favour of its not being 

 dormant in the winter. 



Besides the common species, which is well known, 

 and of which the fur is much used, though not very 

 valuable, there are various smaller species described 

 by Pallas and other naturalists, who have examined 

 the northern parts of Eastern Europe and of Asia. 

 As the manners of these do not appear to differ much 

 from those of the common species, our notice of them 

 shall be brief. 



SAND HAMSTER (Criceti/.i arenarius). This species is 

 said to inhabit mere to the southward than the other, 

 and it is much smaller, not exceeding three inches and 

 a half in length. It has the head oblong, the muzzle 

 pointed ; the extremity of the nose tumid, and reddish 

 coloured ; white mustachios, very furry, and longer 

 than the head ; lips very small ; ears large, oval, and 

 yellowish ; all the upper part of the body of a pearl- 

 gray colour ; the under part, including the flanks, the 

 feet, the tail, and even the claws, pure white. It in- 

 habits the sandy plains, feeding on the roots of vari- 

 ous plants which grow in these places, and also on the 

 seeds of others. This is a nocturnal animal 



Cricctus accedula is considerably srnallar than the 

 hamster. It has the nose rounded, and slightly covered 

 with I'ur, divided by a furrow which also divides the 

 upper lip. The lower lip, and angles of the mouth, 

 are enlarged, and the cheek pouches are very large, 

 extending down both sides of the neck, as far as the 

 shoulders. The mouth, nose, and coverings of the 

 pouches are white, the rest of the body greyish yellow 

 on the upper part, and greyish white on the under. 

 There are two or three other species, but they are 

 small, and not of much general interest. 



CRICHTONITE, a mineral of a velvet black co- 

 lour, so named by Bournon in honour of Dr. Crichton. 

 It occurs crystallised, usually of a very acute rhom- 

 boidal form, and is found in primitive rocks, along 

 with octohedrite, in the different countries where that 

 mineral is found. 



CRICKET. The English name applied to several 

 species of insects belonging to the oriler Orthoptcra 

 and family Achetidce. Thus the common house 

 cricket is the Acheta domeslica, the field cricket, 

 Acheta campestris, and the mole cricket Gryllotalpa 

 vufgaris (Gryllus Gryllotalpa, Linnaeus). All these 

 insects are evidently distinguished by the chirping 

 creaking kind of noise which they produce, whence 

 evidently the origin of the English name. It should 

 be borne in mind, however, especially when consulting 

 foreign works upon entomology, that the criquets of 

 the French authors are different from those of our 

 own language ; our crickets being by them com- 

 monly called Grillons, (and scientifically Gryllus, 

 whereas they ought decidedly to bear the name of 

 Achetce, being the Linnaean Grylli Achet<E,~) whilst 

 the name of Criquet is given to the true locust family, 

 the Locusta of the ancients, and the Gryllus Locusta 

 of Linnaeus. We cannot conceive why authors who 

 have done so much for the science which they have 

 so assiduously cultivated, should yet persevere in so 

 evidently incorrect a nomenclature. 



The cricket family is distinguished from the locust 

 family, as well as from that of the grasshoppers, 

 having long antennae, by having the wings and v ing- 

 covers carried horizontally when at rest. The former 

 extending beyond the latter in slender fillets, and the 

 latter having a small circular space covered with a 

 glassy membrane in the males, which is employed in 

 producing the noise whence the insects have derived 

 their name. As the females are destitute of this, 

 they do not possess the power of chirping ; the tarsi 

 are composed of only three joints. 



As the family AchetidcE was omitted in its alpha- 

 betical situation, we have thus given its characters 

 under the popular heading, rather than omit them 

 altogether. The genera are by no means numerous, 

 namely, the Acheta, Gryllotalpa, Tridactylus, and 

 Myrmecophila. 



In Acheta the legs are slender and formed only 

 for running and leaping ; the females are provided 

 with a long and slender exserted ovipositor at the 

 extremity of the body, and the antennae are very long 

 and slender. 



The house cricket (Gryllus dmnesticus, Linnaeus; 

 Acheta dmncstica, Fabricius), is too well known to 

 need much description. It is of a yellowish buff 

 colour, varied with brown, and frequents the interior 

 of our houses, especially where fire is continually 

 kept, burrowing behind the chimney and grate, and 

 multiplying in such situations to such an extent, that, 

 independent of their disagreeable chirping (which, as 



