EXPERIMENTS WITH STAG-BEETLE, ANTS. 43 



the case, and that in them the sense of smell does 

 reside in the antennae. 



That the stag-beetle can smell seems clearly proved, 

 but Landois found * that, after the removal of the 

 terminal plates of the antennae, the insect still possessed 

 this faculty, whence he concluded that the sense of 

 smell must reside in some other part of the body, and 

 that the antennae probably serve as organs of hearing. 

 This does not, however, prove that the sense of smell 

 does not reside partly in the antennae. 



Forel removed the palpi and mouth parts of a wasp, 

 and she appeared to perceive the presence of honey as 

 well as before. 



I myself took a large ant {Formica ligniperda), and 

 tethered her on a board by a thread. When she was 

 quite quiet, I tried her with tuning-forks ; but they 

 did not disturb her in the least. I then approached the 

 feather of a pen very quietly, so as almost to touch 

 first one and then the other of the antennae, which, 

 however, did not move. I then dipped the pen in 

 essence of musk and did the same ; the antenna was 

 slowly retracted and drawn quite back. I then repeated 

 the same with the other antenna. I was, of course, 

 careful not to touch the antennae. I have repeated 

 this experiment with other substances with several 

 ants, and with the same results. Perris also made the 

 same experiments with the palpi, and with the same 

 result ; but if the palpi were removed, the rest of the 

 mouth gave no indications of perceiving odours. 



Graber f also has made a number of experiments, and 



* "Das Geliurorgan des Ilirschkafers," Arcli. fiir. Mic. Anat, 1868. 

 t "Vergl. Grand versuche uber dio Wirkung und die Aufnalime- 

 stellen chemivscher Eeize bei den Tliieren," Biol. Centralblatt, 1885. 



