THE MOUTH. 63 



case. The antenna was 3-jointed, the two apical seg- 

 ments presenting the same peculiarities as in the 

 preceding specimen. At the next moult the terminal 

 segment elongated as in fig. 7 ; but no further change 

 took place. 



I made a few more similar experiments with similar 

 results, but was reluctant to multiply them too much, 

 being nnwilling to cause unnecessary pain, and seeing 

 no reason to expect any materially different results. 



It is remarkable that in all these cases the terminal 

 segment acquires a length even greater than that 

 which it possesses in normal specimens. This is well 

 shown also in Tomocerus. In this genus I have satisfied 

 myself, both by direct experiment, and also by 

 watching specimens which had been accidentally muti- 

 lated, that if the terminal segment is removed it is never 

 replaced, though the third segment acquires an unusual 

 length. I have even seen specimens, under these circum- 

 stances, in which the third segment acquired a length 

 almost equal to that of the third and fourth segments 

 of a normal antenna. 



The descriptions given by difierent naturalists of the 

 mouth-parts of these animals have been v^ery dissimilar. 

 Fabricius mentions mandibles and maxillae, labium and 

 two pairs of palpi, consisting respectively of five and 

 three segments. Latreille does not hesitate to charac- 

 terise this description as being " absolument fictive." 

 Assuredly it is absolutely incorrect ; but is it not more 

 probable that Fabricius should have mistaken the 

 species he examined, than that this great naturalist 

 should have voluntarily committed a fault so certain of 

 detection ? 



The account given by Latreille himself is little more 

 satisfactory. " La levre inferieure," he says, " se com- 

 pose de deux petites lames longitudinales, paralleles, 

 avec trois ou quatre divisions setacees, au bord 

 superieur de chaque, et dont Tune est peut-etre un 

 palpe. Quelques autres pieces, et qui, a en juger par 

 la couleur brune, on tirant sur celle de la corne, de leur 



