1 984 Insects. 



suit of the superiority of their organization and its physiological consequences, though 

 chiefly from their sensibility to external influences, they are unable to endure certain 

 low degrees of temperature wherein many plants will grow and perpetuate their spe- 

 cies. Thus, at the culminating points where Ranunculus glacialis and Saxifraga 

 groenlandica are found, that is to say at an elevation of about 3000 metres, I have 

 never met with insects permanently established, such as certain Carabites, Cureulio- 

 nites and Forficulites, whose young are freely produced 500 or 600 metres lower 

 down ; the entomologist would consequently lose both his time and his labour in 

 hunting for these on the summits of the Pic d'Ossan, of the Monne, of the Pic de 

 Gere, of the Piquette d'Endrellits, the Pic du Midi, &c. He might by chance, on 

 some sunny day towards the end of August, capture a rapidly flying Bombus, which 

 had ventured into those elevated regions to plunder their flowers, or he might meet 

 with a common Syrphus, or a butterfly belonging to the embrowned genus of Satyrus, 

 rapidly traversing such localities and eluding attempts to enclose it in the net. 



" The climatal conditions of these altitudes are incompatible with the maintenance 

 of animal life in insects with a permanent domicile. Snow which covers the summits 

 of mountains and their approaches for at least half the year, is opposed to all the ne- 

 cessary conditions of life and means of subsistence of the perfect insect, and more es- 

 pecially to those of the larva, whose power of locomotion is more restricted, and its 

 susceptibility much greater. Thus the region called by botanists the upper alpine 

 zone would yield nothing or next to nothing to entomological researches. 



" Plants, by the normal development of their periods of evolution, appear to me to 

 define, much better than all the lines laid down upon maps, the general mean tempe- 

 rature and the climatal constitution of localities. Under these two relations, the palm, 

 the olive, the fig, the maize, the vine, the oak, the beech, the birch, the fir, the rhodo- 

 dendron, the Ranunculus glacialis, &c, are to me more significant, more veridical, 

 than degrees of latitude, longitude, and altitude, which necessarily lose somewhat of 

 their mathematical precision when the question of the variable locality of a vegetable 

 or animal organism is under consideration. Vegetation in itself, either directly or in- 

 directly, influences the existence of insects. Those insects which are essentially phy- 

 tophagous, seldom pass by a plant adapted for their support; and when the particular 

 species best fitted to supply their wants is absent, by an admirable and providential bo- 

 tanical instinct they know how to have recourse to another species of the same genus, 

 or, in default of this, to another genus of the same family. And as to insects destined 

 to feed upon living prey, or to exist in some organic detritus, they also are in like man- 

 ner amenable to the influence of the harmonions law of nature." 



M. Dufour establishes two entomological zones for Pyrenean insects. 



" 1 . The sub-alpine entomological zone. This comprises not only the forests of beech 

 and fir, but the bogs and water, in short all the country below and of an equal altitude 

 with these forests. 



"2. The alpine entomological zone. This rises above the pine forests and com- 

 mences with the rhododendron — the only social shrub of the Pyrenees." — Revue 

 Encyclopidique, May, 1847. 



Capture of rare Insects in JEngland and Scotland. — It may be useful to your ento- 

 mological friends to know that the following rare insects have been taken in England 

 and Scotland. 



Lophyrm Pini, Linn., Lophyrui paltidus, Illig. I bred both sexes in 1846 from 

 caterpillars collected in Scotland. 



