930 Journal of a Trip to the Burenda Pass in 1836. [Nov 



formation or production of a perfect and healthy insect, as food is to the larva. 

 If moisture be withheld, the skin of the pupa shrinks and hardens and the insect 

 has not room to expand and perfect its parts. 



From this cause I am led to believe that many varieties, have been unneces- 

 sarily raised into species and described as distinct. 



The mere circumstance of their differing in size and proportions can never 

 really separate them ; as well might two brothers be deemed of distinct species 

 because the one happens to be six feet in stature and the other a dwarf. Such 

 a comparison is by no means absurd, because many of the ova deposited by our 

 female, will eventually produce large and well-formed insects, and the rest produce 

 their diminutives. These, therefore, can never be received as more than mere 

 varieties of each other, and indeed I can scarcely consider the offspring of the 

 same parents as varieties at all. The offspring of two females of the same species 

 may possibly be reckoned as varieties of the same, should they happen to differ ; 

 but surely the hildren of one mother, produced at one birth, must be to all 

 intents and purposes one and the same species. 



Thus when two insects of the same species differ merely in size and the greater 

 or lesser development of horns, spiny or other processes, they may be termed 

 " Varieties." But a difference in structure, habits, food or general economy 

 would alone authorize their being classed as distinct species. By difference in 

 structure, I would be understood to mean, of different forms, because the mere 

 circumstance of a horn or spine being greater or less, in some, than in others 

 does not constitute a different, but only a greater or less development of the same 

 structure. 



It is perhaps a remarkable fact, that almost every species of Coleoptera, has its 

 diminutive, and the only way, in which to account for this lies, I think, in the 

 abundance or scarcity of proper nourishment they receive in the larva and pupa 

 states. 



While speaking of insects, it may be as well to observe that it has hitherto 

 been received as a rule, that sexual commerce is unknown to the larva state ; 

 this rule cannot now wholly apply, as during the past year, I have repeatedly seen 

 the larvae of a species of grasshopper in connexion during the summer months, at 

 Simla. 



4 Land Snails. — Two species ofNanina, one (or two) of Bulimus (reversed) and 

 one of Clausilia, being new to science, will, with many others, shortly be 

 described in a separate paper and submitted to the Asiatic Society. u Clausilia 

 elegant," nobis, is sadly destructive to the oak of these mountains, which they 

 seem to prefer to all other trees. They bore into every crevice and live in the 

 rottenness they have created, grinding and reducing the fibre of the wood to the 

 consistency of wet sawdust. 



In the 3rd No. of the Journal of the Asiatic Society, Dr. Roylb observes, 

 that the shells of these mountains do not differ from those described by Mr. 

 Bjsnson as occurring in the Gangetic provinces. Of twenty species which 



