Saurian ? Reptiles^ Insects. 247 



of the Sd it was still 16° Reaum., or 4° Fahr.; and at the 

 same hour several thermometers in the neighbourhood of 

 Berne marked 24° Reaum., or 22° Fahr. The succeeding 

 summer was as productive as usual of insects ; not only of 

 those which are hatched from the eggy but also of those which 

 hibernate in the pupa state. I have, however, remarked a 

 singular fact, namely, that, during the year 1832, a sharp 

 look-out only enabled me to find one, and that a feeble 

 individual, of Melolontha vulgaris, usually very abundant, 

 and having a marked inclination for a particular plum tree in 

 my orchard ; a vigilant search failed to procure me a single 

 Zucanus Cervus. A neighbour and myself, aided by a troop 

 of young foragers, were not able to obtain more than seven 

 full-grown larvae of Cossus ligniperda ; and Cetonia aurata, 

 and some other species which pass three years in the larva 

 state, were, although not quite so deficient as the ikTelolontha 

 vulgaris, the iucanus Cervus, and the Cossus ligniperda, deci- 

 dedly far less numerous than usual. Are we to conclude from 

 this, that, although intense cold fails to destroy the eggs, full- 

 grown larvae, or pupae, it is fatal to the young larvae of such 

 species as pass three winters in their first state of existence ? 



I should be glad to know whether this circumstance has 

 been noticed elsewhere : but the observations, to be conclusive, 

 must have been made in a district which was exposed during 

 some time to a temperature not higher than zero of Fahr., as 

 our experience of our ordinary winters proves that a degree 

 of cold occasionally only equal to zero is but little fatal to 

 the insect world. On the 25th of February, 1830, Fahrenheit's 

 thermometer being at 60°, Vanessa urtlcae and Gonepteryx 

 rh^mni were on the wing ; having, I presume, safely passed 

 the winter term in the pupa state. Writers on entomology 

 generally speak of these early visiters as unimpregnated fe- 

 males, which, having issued from the chrysalis in autumn, after 

 the disappearance of the males, have lived through the win- 

 ter in the perfect state ; and the circumstance is adduced as a 

 wonderful instance of an extraordinary prolongation of life, 

 granted, by an omnipotent and beneficent Providence, to indi- 

 viduals produced at a season when the purpose for which 

 that life was bestowed could not be accomplished in its ac- 

 customed period. I by no means call in question the cor- 

 rectness of this opinion in its general application, not having 

 particularly noticed the subject, except during the last few 

 years ; and I consider that observations made in one place, or 

 in one climate, are insufficient either to establish or refute a 

 general fact. In most parts of Switzerland the rule certainly 

 does not apply ; and I would caution young entomologists 



V. 4 



