140 TENTH ANNUAL REPORT OP 



spinner ; slie then introduces bubbles of air, and soon has a commo 

 dious and dry retreat in the water. 



The means of defence which insects employ were also considered. 

 They assume various attitudes calculated to deceive the beholder ; 

 many roll themselves up and feign death. One genus, BracJiinus, has 

 'the wonderful faculty of producing a sound (but not from the mouth) 

 like the explosions of a pop-gun, and a smoke-like secretion is at the 

 same time discharged. Other insects eject an acrid fluid from their 

 mouths ; some defend themselves with their weapons ; some have 

 horns and strong claws ; some have stings ; some bite — others pierce ; 

 bees erect fortifications at the mouth of their hives to defend them- 

 selves against their enemy, the moth ; some cover themselves with 

 leaves ; some appear only at night, &c., &c. 



Numerous instances of the remarkable instincts of insects were 

 given, and among them that of the common mosquito in the laying 

 of its eggs. The female poises herself lightly on the water, protrudes 

 her hinder legs crosswise, and deposites her eggs on the platform thus 

 formed ; and when she has laid all, to the number of tliree hundred, 

 she lets the mass drop on the water, where they are hatched, and in 

 which they are destined to live in their larva state. This mass of 

 eggs is not a misshapen cluster, but it has the regular form of a boat, 

 and is so well poised that the most violent agitation of the water can- 

 not overset it. If it sunk, the eggs would perish ; but they float until 

 they are hatched, and then the young find their destined place in the 

 water, in wliich they undergo their transformation. Other examples 

 of instinct of caterpillars, wasps, ants, moths, &c., were given. 



This led the lecturer, in conclusion, to say something on the nature 

 of instinct itself. 



The French naturalist, Bonner, has said that philosophers will in 

 vain torment themselves to define instinct, until they have spent some 

 time in the head of an animal, without actually being that animal ! 

 Cudworth referred this faculty to a certain pZastic wa/wre; and Des 

 Cartes maintained that animals are mere machines. Mylius, an old 

 philosopher, thought that many of the actions deemed instinctive are 

 the efi"ect of painful corporeal feelings ; the cocoon of a caterpillar, for 

 instance, being the result of a fit of cholic ; the animal producing the 

 cocoon by its uneasy contortions, and thus twisting its superabundant 

 silk material into a regular ball. Some have thought that the brain 

 of a bee or spider is impressed at its birth with certain geometrical 

 figures, according to which models its works are constructed. Buffon 

 refers the instinct of societies of insects to the circumstance of a great 

 number of individuals being brought into existence at the same time, 

 all acting with equal force, and obliged, by the similarity of their 

 structure, and the conformity of their movements, to perform each the 

 same movements in the same place, whence results a regular, well- 

 proportioned, and symmetrical structure. Addison and some others 

 have thought, as Kirby reports, that instinct is an immediate and con- 

 stant impulse of the Deity. The only opinion which deserves serious 

 consideration is that which contends for the identity of instinct with 

 reason in man. Some great names are arranged on this side, and it 



