52 



ZOOLOGY 



Fig. 55. — Polistes. 

 Sli^itly reduced. 

 Photo. Ijy W. H. 

 C. P. 



nearly spherical gray paper envelope (Fig. 56). These are 



found attached to tree.s or parts of buildings. The paper is 

 made of finely masticated wood-fibre cemented 

 l.)y a secretion. Certain yellow-jackets form 

 nests in the ground. The hornets are well 

 known as among the most vindictive of our 

 northern insects, and their sting is capable of 

 producing considerable pain. In all Hymenop- 

 tera the pain of the sting is due to the introduc- 

 tion of a poison into the l)ody of the victim 

 through the stinging organ. This poison is 

 secreted l)y a special gland of the insect. 

 The digger and mud wasps (Fossoria 'j have the most varied 



habits. One of the most familiar species is Pelopmus,- which 



somewhat resemljles a true wasp, 



but may be easily distinguished from 



it by the long, slender attachment of 



the abdomen to the 



thorax and b\' the 



fact that the TOngs 



when closed lie fiat 



and horizontal (Fig. 



•57), while in the true 



wasjis they are folded 



like a fan. Other species bore into the pith of 



Nat. size. Piioto. plants or make burrows in the ground. INIanv 

 byW. H. f. p. , , ,. ., . , ' 



are predaceous, leedmg on sjuders, cicadas, etc. 



The ants (Formiciihe '') constitute a well-known group hav- 

 ing features so marked thatother insects, excepting the termites, 

 will hardly be confused with tliem. From the termites ants 



1 From .foM,or, digger. "^ pelos, slime. = From /orm/ca, ant. 



gor 



Fig. 57. — Di 

 WLisi', sliowiii 

 position of miiL^s 



Fig. 50. — VesiKi, a 

 Nat. size. Pboto. 

 H. C. P. 



hornet. 

 l:.y W. 



