By the Rev. T. A. Marshall. 55 



wisdom and the usefulness. It will be enough to prove a case for 

 usefulness, when wisdom follows naturally ; since no one will deny 

 that it is wise to seek whatever is useful. Without entering far 

 into an inexhaustible subject, which has long ago filled volumes, I 

 will take a single department of the science, now called economic 

 entomology. This has to do with the injuries and benefits which 

 the human race receives from the race of insects. These creatures, 

 however weak individually, constitute collectively one of the great 

 powers of Nature, which man is obliged to respect ; he must either 

 learn to control it, or he must take refuge in flight. It is hardly 

 too much to say that we hold our place on sufferance ; our presence 

 is tolerated. It is within the resources of insect power to render 

 any given country uninhabitable ; to break the staff of bread in that 

 country ; to realise the terrors of Egypt ; to spread death among 

 flocks and herds ; to rot the forest trees, and blight the produce of 

 the garden, together with the hopes of the farmer. I must not go 

 into details, but anyone will readily recall accounts of the ravages 

 of many species of locust (no traveller's tales, as is often supposed) ; 

 the cattle-destroying tzetze ; the Colorado beetle, which has already 

 sent out spies to view the British Islands ; the Phylloxera vastatrix, 

 which has a price of £25,000 set upon its head by the Australian 

 Governments, and 300,000 fr. by that of the French Republic. The 

 bleak and watery climate of Great Britain might be supposed to 

 offer a substantial check to the destructive forces of insects ; and to 

 some extent this is the case: yet insects have ruined many an 

 English family. Our cereals, turnips, hops, and fruit trees, are all 

 at their mercy, and the partial failures that occur annually shew what 

 ravages, under unfavourable circumstances, are conceivable. We 

 have also innumerable enemies of minor importance, who, if unable 

 to ruin our fortunes, attack our persons, invade our dwellings, 

 plunder our larders, and render domestic life, in some countries, a 

 perpetual skirmish. It is not my intention, however, to make a 

 catalogue of plagues; a brief allusion to them is enough to shew 

 the necessity of organised resistance, with whatever of labour, ob- 

 servation, and experiment may be required to render it efficacious. 

 On the other hand the advantages which men derive from insects 



