342 NATURAL SCIENCE [November 



Solitaey Wasps 



The Instincts and Habits of the Solitary Wasps. By George W. Peckham and 

 Elizabeth G. Peckham. 8vo, pp. 245 ; 14 plates (2 coloured). Wisconsin Geo- 

 logical and Natural History Survey Bulletin No. 2. Scientific Series No 1. 

 1898. 



In discussing the problem of Instinct, Darwin wrote, "If it can be 

 shown that instincts do vary ever so little, then I can see no difficulty 

 in natural selection preserving and continually accumulating variations 

 of instinct to any extent that was profitable." This sentence might 

 well serve as the text for the charming book before us, and seems to 

 have been ever present in the minds of our authors during many 

 hours spent in the sweat of the brow, in trying postures, and under a 

 blazing sun in the successful endeavour to learn something from the 

 Solitary Wasps haunting a garden in Wisconsin. The result of their 

 toils may be given in their concluding words : — " The general impres- 

 sion that remains with us as a result of our study of these activities 

 is that their complexity and perfection have been greatly over- 

 estimated. We have found them in all stages of development, and 

 are convinced that they have passed through many degrees, from the 

 simple to the complex, by the action of natural selection. Indeed, 

 we find in them beautiful examples of the survival of the fittest." 

 This is a striking contrast to Fabre's remark that had Darwin 

 known the results of his latest observations on the stinging 

 habits of Solitary Wasps, he would have frankly avowed his in- 

 ability to make instinct enter the mould of his formula. Mr and Mrs 

 Peckham show conclusively that the popular belief that these wasps 

 sting their prey for the purpose of paralysing but not killing, in 

 order that a fresh and not putrid supply of food may be at hand for 

 the offspring is far from correct. Great stress has been laid upon this 

 hitherto accepted belief by Eimer, Eomanes, and others, and in view 

 of its wide acceptance among zoologists and the general public it is 

 worth giving a brief outline of the results of our authors' observations 

 on this phenomenon. Out of forty-five species of Solitary Wasps 

 observed by them about one-third kill their prey outright. Of the 

 remainder there is not a single species in which the sting is given 

 with invariable accuracy ; in fact, they scarcely sting twice alike since 

 the victims of the same wasp may be killed at once, or may live from 

 one day to six weeks, or even ultimately recover ; and this even after 

 treatment by the most skilled surgeons in the hymenopteron world. 

 It is thus at once evident that the sting is not invariably thrust with 

 unfailing accuracy into the nerve centres, and, further, that dead meat 

 is quite as acceptable to the larvae as living flesh — as indeed was 

 fully proved by actual observation. It is of great interest to find that 

 the poison of the wasp's sting has a great paralysing power when in- 

 troduced into the body of the victim at any point, so that the prey is 

 rendered helpless without the necessity of a complete knowledge of 

 invertebrate anatomy on the part of the wasp. Thus, a leg was 

 broken off a small cray fish, and a Polistcs fusca made to thrust its 

 sting into the exposed end of the stump, with the result that the cray 

 fish was instantly paralysed and died after a few hours. Similar 

 results followed from causing a Polistes to sting a large spider in 



