54 Mr. W. E. Shuckard o» the Habits 



Le Pelletier de St. Fargeau, unless previously restricted within certain 

 limits, — which, I hope, I am enabled to do with precision, from the 

 knowledge obtained from that only safe source, the patient and at- 

 tentive observation of nature ; truth, and not theory, being the object 

 of my quest. 



The study of structure frequently either leads to the corroboration 

 of observations upon the oeconomy of insects, or throws out sugges- 

 tions which experience confirms. This has been remarkably the case 

 with the Aculeate Hymenoptera. The Rev. Mr. Kirby, whose work 

 I so recently mentioned, was induced to surmise, from the absence 

 of polliniferous instruments in the genus Melecta, one of the bees, 

 that it might be a parasite upon another of the family ; and this 

 supposition derived additional strength from its being found by Mr. 

 Trimmer in the nest of Anthophora retusa, which subsequent obser- 

 vation ascertained to be the insect whereon it was parasitic. Several 

 other genera of bees are in the same predicament ; but no investiga- 

 tions hitherto made will enable us to ascribe these cuckoo bees to their 

 relative fosterers. (See Note 1.) But the term parasite must be here 

 understood in a different acceptation to which it is received in refer- 

 ence to the Ichneumones and the ChalcididcE , these being strictly in- 

 ternal parasites; whereas the larva of the parasitic bee or wasp is sup- 

 ported at the expense of the larva of the insect which collected the 

 food, by consuming what she had laid up for the use of her own pro- 

 geny. This naturally suggests the idea that the egg of the parasite 

 may possibly be disclosed more rapidly than that of the insect which 

 laid up the store; but of this we have no certain knowledge, nor in- 

 deed of anything that takes place within the nest : but that the larva 

 of the parasite is carnivorous, may, I think, be absolutely negatived 

 with respect to the bees ; and, therefore, although the food is con- 

 sumed, the larv^a itself is left untouched, but is starved to death in 

 consequence of the failure of its supplies : but with respect to the 

 wasps, I have not the least doubt that the heir is consumed as well 

 as his inheritance. 



M. de St. Fargeau followed up this hint upon perceiving, in his 

 examination of the structure of the Fossorial Hymenoptera, that some 

 possessed the anterior tarsi ciliated on the outside ; and when thus 

 armed, the posterior tibiae were likewise furnished, through their 

 whole length, also on the outside, with spines or teeth : but in others 

 the cilia were wanting, and, that, always when thus formed, their con- 

 comitant, the spines of the hinder tibiae, were either deficient or obso- 

 lete. "Well acquainted with the burrowing habit of the majority of 

 these insects, he was induced to infer that the cilia of the tarsi were 

 employed to facilitate the insect in forming its burrows, and that the 



