Note B. 337 



they are recognized as assumptions ; but so long as the very 

 question in debate has reference to their vahdity as assumptions, 

 it is closely illogical to adduce them as arguments. And this 

 is the only point with which we are at present concerned. 



Note B to Page 89. 



In answer to this illustration as previously adduced by me, 

 Mr. Poulton has objected that the benefit arising from the 

 peculiar mode of stinging in question is a benefit conferred, 

 not on the insect which stings, but upon its progeny. The 

 point of the illustration however has no reference to the 

 maternal instinct (which here, as elsewhere, I doubt not is 

 due to natural selection) ; it has reference only to the particular 

 instinct of selective stinging, which here ministers to the pur- 

 poses of the other and more general instinct of rearing progeny. 

 Given then the maternal instinct of stinging prey for the use 

 of progeny, the question is — What first determined the ancestors 

 of the Sphex to sting their prey only in nine particular points ? 

 Darwin's answer to this question is as follows : — 



" I have been thinking about Pompilius and its allies. Please 

 take the trouble to read on perforation of the corolla by Bees, p. 435 

 of my ' Cross-fertilization,' to end of chapter. Bees show so much 

 intelligence in their acts, that it seems not improbable to me that the 

 progenitors of Pompilius originally stung caterpillars and spiders, &c., 

 in any part of their bodies, and then observed by their intelligence 

 that if they stung them in one particular place, as between certain 

 segments on the lower side, their prey was at once paralyzed. It 

 does not seem to me at all incredible that this action should then 

 become instinctive, i. e. memory transmitted from one generation 

 to another. It does not seem necessary to suppose that when 

 Pompilius stung its prey in the ganglion it intended or knew that 

 their prey would keep long alive. The development of the larvae 

 may have been subsequently modified in relation to their half-dead, 

 instead of wholly dead prey ; supposing that the prey was at first 

 quite killed, which virould have required much stinging. Turn this 

 over in your mind," &c. 



II. Z 



