XXX11 



INTRODUCTORY REMARKS. 



thousand feet above the sea. The greater number, however, delight 

 in barren, stony places near the coast, where wind and sunshine 

 seldom cease to fight for the mastery in either stunting or developing 

 their growth. 



No one who believes in the adaptation of insect life to every 

 special department of the vegetable kingdom could fail to anticipate 

 the existence of a curious fauna attendant upon this remarkable 

 assemblage of viscous shrubs. Yet I must own to considerable dis- 

 appointment when, in company with Mr. Gray, I first penetrated 

 (at the Canaries) into a thicket of them and found absolutely nothing. 

 Still, however, I felt firmly persuaded that such an important set of 

 plants could hardly occur without, at any rate, a certain number of 

 Coleopterous parasites ; and we concluded therefore that the speci- 

 mens in sound and vigorous health, such as those which we had 

 examined, were not the ones likely to satisfy the requirements of 

 an entomologist. Unfortunately, however, the old and decayed stems 

 are much sought after for fuel, and so were not readily to be met 

 with ; but when at length (in the north of Lanzarote) we came upon 

 a quantity of them, erect and undisturbed, all doubt as to their pro- 

 ductiveness was at an end. From that time I made it a constant 

 practice to overhaul the dead Euphorbias, whenever they came to 

 hand ; and it is surprising what a number of Coleopterous insects 

 are supported by them, which we might in vain look for in any 

 other situation. Already indeed about 50 species have been brought 

 to light, which would appear to be exclusively of Euphorbia-infesting 

 habits; and we may be sure that many others yet remain to be 

 found. But what struck me most, is the incredible mass of indivi-. 

 duals by which some of them are represented ; for the Aphanarthra, 

 particularly, are often in such multitudes that the rotten stalks and 

 branches seem absolutely alive with them. And yet, in spite of 

 this, so confined are they to that actual group of plants that, unless 

 the latter be examined rigidly, one might ransack the islands from 

 end to end and not obtain even one of them. And so also the 

 Mesites euphorbice in Madeira and the M. fusiformis in the Canarian 

 Group, which are well nigh universal amongst the decaying Eu- 

 phorbia-stems, are marvellously abundant; whilst the same might 

 be said of the Europs impressicollis, which I feel satisfied will be 

 found to permeate the entire archipelago. The following list, how- 

 ever, will show what the exact species are which have been ascer- 

 tained to frequent the Euphorbias ; but as my object is to register 

 everything which (so far as observed hitherto) a collector would be 



