1 96 Miscellaneous. 



Haliclus sexcinetus has Myodites svbdipterus as a parasite. The 

 larva of this curious fly-like beetle devours the larva or the Hyuieno- 

 pteron when the latter h;is finished its provision of honey. The 

 author does not yet know how the parasitic worm-like creature, 

 which is incapable of progression, is introduced into the cell of the 

 Hal ictus. Perhaps there may be here an initial transfiguration, and 

 habits having some analogv to those of the Meloi'des. — Comptes 

 Rendus, Dec. 22, 1879, p. 1079. 



On the Locomotion of Insects- and Arachnida. 

 By M. G. Cablet. 



The mode of locomotion of insects and Arachnida is much more 

 regular than is usually supposed. The only rule laid down by 

 authors is that the two legs of the same pair never move simul- 

 taneously. By examining insects the movements of which arc slow 

 and the legs equidistant, such as Orijctes nasicomis and Timarcha 

 tenebrieosa, we see that the limbs move as indicated in the 

 following table, in which the legs are arranged in their natural 

 position, and the numbers indicate the order in which they are 

 raised :• — ■ 



5 >2 

 3/ 6 



Whilst the legs 1, 2, 3 are raised almost simultaneously, the legs 

 4, 5, 6 remain in support, to be raised in their turn when the 

 former have come to rest. In other words, the insect rests upon a 

 triangle of sustentation formed by the two extreme feet of the same 

 side and the middle foot of the other side, while it moves forward 

 the other three feet. I have ascertained that this mode of locomo- 

 tion is equally characteristic of the other orders of insects. 



Arachnida . — I have been able to follow very clearly the order of 

 movement of the legs in the female of Epeira diadema. It is 

 almost impossible to catch this order in male spiders, in consequence 

 of the rapidity of their progression. In the females the voluminous 

 abdomen forms a burden which retards movement and enables the 

 following table to be traced : — 



1\ 5 

 6> 



8 \4 



Here the polygon of sustentation is a quadrangle formed on the 

 one side by the feet of even numbers, and on the other by those of 

 odd numbers. — Comptes liendus, December 29, 1879, p. 1124. 



