72 Some Solitary Wasps of Texas. 



caterpillar lived long after the egg should have hatched, yet in each 

 case the caterpillar was sufficiently stung in the middle segments to 

 insure the proper quiescence. It must be said, however, that the 

 five caterpillars thus observed are not sufficient to yield conclusive 

 results. In this connection we should listen to the Peckhams, whose 

 opinions, diametrically opposed to ihose of Fabre on the question of 

 the stinging and other instincts of wasps, yet seem to me to be well 

 established. Fabre argues that the wasp's actions are the result of 

 an automatically perfect instinct which allows no variations. The 

 Peckhams combat this view, holding that, in their study of wasps, 

 the "one preeminent unmistakable and everpresent fact is variabil- 

 ity; variability in every particular; in the shape of a nest and in the 

 manner of digging it, in the condition of the nest (whether closed 

 or open) when left temporarily, in the method of stinging the prey, 

 in the manner of carrying the victim, in the way of closing the nest 

 and last, and most important of all, in the condition produced in the 

 victims after stinging, some of them dying long before the larva is 

 ready to begin on them, while others live long past the time at 

 which they would be attacked and destroyed if we had not interfered 

 witli the natural course of events. And all this variability^ we get 

 from a study of nine wasps and fifteen caterpillars." 



Fabre's opinion of the instinct of wasps has long been the jjrevail- 

 ing one among naturalists. Romanes depended on Fabre for his 

 information. The question would not have been dreaded by Dar- 

 win but welcomed with delight had he been aware of the facts as 

 afterward presented by the Peckhams. The central point from 

 which the influences of the older naturalists were drawn, was the 

 assumption that the larvae must be nourished upon fresh food. 



The fact is now, however, fully established that the larva thrives 

 quite as well upon dead as upon living food. 



The study of the habits of animals is, indeed, a most fascinating 

 branch of zoological work, and the solitary wasps, though so little 

 studied, are among the most interesting objects of study owing to the 

 great variety of their activities. As to the result to be derived from 

 a study of their habits, the solitary wasps may be expected to con- 

 tribute no small quota toward the solution of the psychological 

 problems concerning the lower animals. 



