254 



NA TUBAL HIS TOR Y. 



leaf or spear on which the animal rests. It sucks in the juices of the 

 grass, and after having absorbed the nutriment from them it expels 

 the water together with a considerable quantity of air, thus producing the 

 peculiar frothy appearance. 



The general shape of these small, inconspicuous bugs is shown by the 

 adjacent cut, which represents a little form which at times proves very 

 injurious to the grape-vine. The colors of this, as well as of 

 the allied species, are very variable, and but little dependence 

 can be placed upon them in the description of any form. 

 Yet many of these small species, when viewed by a common 

 hand-lens, will be seen to be exceedingly beautiful, their colors 

 being bright and harmonizing and laid on in pretty patterns. 

 All the forms of bugs so far enumerated belong to one 

 group, which have the first pair of wings of homogeneous 

 fig 239 — Grape- texture throughout, while those which remain to be enu- 

 7/^ hop £ e !,;^rr merated have them half coriaceous, half membranous, as 

 was mentioned on a preceding page. Of these latter forms 

 — the true Hemiptera — we find forms which are beneficial and forms 

 which are injurious to vegetation, although none of them have any com- 

 mercial importance to be compared with that of the lac- 

 insect or cochineal. 



First of them are a number of aquatic, rapacious forms 

 which rival the water-beetles in their predaceous habits. 

 Some of them swim in the normal position, while others, 

 also natatory in habit, always go upon their backs ; some F ^- ?socydtumf' 

 creep about the bottom ; others are adapted for walking 

 on the surface. Some of them are very large, and their long and strong 

 beaks are capable of inflicting a very severe wound. Fishes are their 



especial prey, and they kill them by 

 inserting this long beak and then 

 sucking the blood. Distantly allied 

 to some of these species of our ponds 

 and brooks is a group remarkable 

 from the fact that it lives and breeds 

 upon the surface of the ocean hun- 

 dreds and even a thousand miles from 

 land, and thus has introduced some 

 modifications of structure exceedingly interesting to the scientist. 



The remaining forms are terrestrial, and a large proportion of them 

 are of value to mankind from the fact that they prey upon other insects, 

 piercing either the larva or the adult with their sharp beaks. Of these 



Fig. 241. — ' Water-scorpion ' (Notonecta) ; dorsal 

 and ventral views of two different species. 



