1880.] TRANSACTIONS. 61 



periods of their migrations, in Autumn and Spring ; that is to say 

 wlien most insects are infinitely less numerous than during the Sum- 

 mer. At other times, they live in couples, usually scattered, but sel- 

 dom in cultivated grounds ; while insects invade in swarms the trees 

 which they wish to attack, — the products of the earth of which they 

 aie foes. 



2d, — Birds destroy enormous numbers of insects : but, of those 

 insects, many are of no consequence ; others are eminently useful ; and 

 the species actually noxious, compared with the aggregate, are so 

 slightly reduced that the birds, though making a great consumption of 

 these little creatures, aid us but little. They even injure us, — many 

 of them devouring our fruits, as well as the grain sown in the earth, or 

 harvested ; and all of them destroying multitudes of insects that, as 

 flesh-eaters or parasites, render us great service. 



3d, — The insects whereof we have most to complain, are, — some 

 large enough to defy birds ; others (and these are usually the most 

 formidable), too small to attract their notice ; still others of too dis- 

 gusting a flavor to excite their appetite ; many are nocturnal, and con- 

 ceal themselves by day, with that instinct of self-preservation which is 

 as well developed among them as among the larger animals ; or, keep- 

 ing motionless, do not reveal themselves to the eye of the bird which 

 easily detects and greedily pursues insects on the wing or in motion. 

 Some live under ground, or in dwellings ; all are endowed with a 

 fecundity that astonishes even the imagination and which, in all cases, 

 is such that man, in spite of his utmost assiduity and perseverance, 

 even in garden cultivation, cannot relieve himself from them, — often 

 cannot free his house from them, — may I not say — a single room in 

 his house ? 



4th, — Cateipillars and worms, — the chief woikers of mischief, 

 usually live concealed under ground, beneath the bark of trees, in the 

 depths of the woods, in the stalks of plants, in fruit, — in places that 

 are inhabited. They are concealed or protected by silken webs and 

 yield but a slight tribute to birds. Those which are developed in the 

 open air, are generally bristling with a skin that repels attack ; some 

 are nocturnal and disappear before dawn ; their very minuteness pro- 

 tects others. 



When we reflect upon these considerations — the fruit of experience ; 

 when we would subject them to a rigid scrutiny, with the desire, if 

 possible, of finding them unfounded ; nevertheless without precon- 

 ceived ideas and with the intention of knowing the truth ; I doubt not 

 that you will adopt my opinion and that even those who are most par- 

 tial to birds will admit that they had not thought Of all this. For 

 myself I am so thoroughly convinced that I dare, without presump- 

 tion, to challenge contradiction and to defy criticism. 



But, you will say, — cannot the cultivator expect any help but from 

 himself? I have already declared, at the outset, that the ability of 

 man to contend with Insects is strongly doubted : and that it has been 

 the inadequacy of his efibrts, the careful observation of facts, which 

 have forced this painful conclusion at the very time that there was 

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