270 TEXT-BOOK OF ENTOMOLOGY 



tera, besides Julus and Lithobius, while many larvae reacted in the 

 same manner. 



Less satisfactory were the experiments with Carabus, Melolontha, and Silpha ; 

 there is no doubt that the species of these genera, through the extirpation of 

 their antennae, become more or less injured as to the acuteness of their powers 

 of smelling ; but they never show themselves wholly unable to perceive strong- 

 smelling substances. 



The allurement of the substance acts for a longer time on those deprived of 

 their antennae, then they become restless, then they wander away from the glass 

 tube held before them ; still all their movements are but slightly energetic, and 

 the entire reaction is indeterminate and enfeebled. 



Experiments with the Hemiptera gave still more unfavorable results ; after 

 the loss of their antennae they reacted to smells as eagerly as those did which 

 were uninjured. 



Experiments on the use of the antennae in seeking for food. Under 

 this head experiments were made with Silpha, Sarcophaga, Calli- 

 phora, and Cynomyia. 



Silpha and its larva were treated in the following manner : they 

 were placed in large boxes whose bottoms were covered with moss, 

 etc. ; in a corner of the box was placed a bottle with a small opening, 

 in which was placed strong-smelling meat. So long as the beetles 

 were in possession of their antennae they invariably after a while 

 discovered the meat exposed in the bottle, while after the loss of 

 their antennae they did not come in contact with it. 



In a similar way acted the species of Sarcophaga, Calliphora, and 

 Cynomyia. Hauser, in experimenting with these, placed a dish with 

 a large piece of decayed flesh on his writing-table. In a short time 

 specimens of the flies referred to entered through the open windoAV 

 of the room. The oftener he drove them away from the meat would 

 they swarm thickly upon it. Then closing the window and catching 

 all the flies, he deprived them of their antennae and again set them 

 free. They flew about the room, but none settled upon the flesh nor 

 tried to approach it. Where a fly had alighted on a curtain or other 

 object, the decayed flesh was placed under it so that the full force of 

 the effluvium should pass over it, but even then no fly would settle 

 upon it. 



Experiments testing the influence of the antennae of the males in 

 seeking the females. For this purpose Hauser chose those kinds in 

 which the male antennae differ in secondary sexual characters from 

 those of the female, and in which it is known that they readily 

 couple in confinement, as Saturnia pavonia, Ocneria dispar, and 

 Melolontha vulgaris. The two first-named insects did not couple 

 after the extirpation of their antennae. Of Melolontha vulgaris 



