Advanced Theories 113 



powerful huntresses, requiring big prey, do not 

 find in these Ruminants of the insect world 

 what we ourselves find in our domestic Rumi- 

 nants, the Sheep and the Ox, peaceable victims 

 yielding plenty of flesh ? It is just a possibility, 

 but no more. 



I have something better than a possibility 

 to offer in reply to another and no less im- 

 portant question. Do the Orthopteron-eaters 

 ever vary their diet ? Should the favourite 

 type of game fall short, can they not accept 

 a different one ? Does the Languedocian Sphex 

 consider that there is nothing in the world 

 worth having but fat Ephippigers ? Does the 

 White-edged Sphex allow none but Locusts to 

 figure on her table ; and the Yellow-winged 

 Sphex none but Crickets ? Or, according to 

 time, place and circumstances, does each make 

 up for the lack of her favourite victuals by 

 others more or less equivalent ? To ascertain 

 such facts, if they exist, would be of the greatest 

 importance, for they would tell us if the inspira- 

 tions of instinct are absolute and unchangeable, 

 or if they vary and within what limits. It is 

 true that the cells of one and the same Cerceris 

 contain the most varied species of either the 

 Buprestis or the Weevil group, which shows that 

 the huntress has a great latitude of choice ; but 

 this extension of the hunting-fields cannot be 



H 



