248 MODIFIABILITY OF INSTINCTS. 



of our present Ammopliilas may have fed tlieir young 

 from day to day with fresh food, as Bembex does even 

 now ; that they may then have gradually brought the 

 provisions at longer intervals, choosing small and 

 weak victims, and layiug the egg in a special part of 

 the cell, as Eumenes does? that during these long 

 ages they may have gradually learnt the spots where 

 tlieir sting would be most effective, and, thus saving 

 themselves the trouble of capturing a number of 

 victims, have found that it involved less labour to select 

 a fine fat common caterpillar, such as that of Noctua 

 segetum, and so have gradually acquired their present 

 habits'? Wonderful doubtless they are; but, though 

 I hint the suggestion with all deference, such a 

 sequence does not seem to me to present any in- 

 superable difficulty. 



This suggestion was made in the Contemporary 

 Bevieiv for 1885, and I was much interested to fiud in 

 Mr. Darwin's life that he had made a similar suggestion 

 in a letter to M. Fabre. He refers to the great skill 

 of the Gauchos in killing cattle, and suggests that each 

 young Gaucho sees how the others do it, and with a 

 very little practice learns the art. "I suppose that 

 the sand-wasps originally merely killed their prey by 

 stinging them in many places (see p. 129 of Fabre's 

 * Souvenirs,' and p. 24.1), and that to sting a certain 

 segment was found by far the most successful method, 

 and was inherited like the tendency of a bulldog to pin 

 the nose of a bull, or of a ferret to bite the cerebellum. 

 It would not be a very great step in advance to prick 

 the ganglion of its prey only slightly, and thus to give 

 its larvae fresh meat instead of only dried meat." * 

 * "Life and Letters of Charles Darwiu." 



