The Glow- Worm and Other Beetles 



Tachytes, the grub, when its heap of Mantes 

 is consumed, moves from cell to cell until it 

 has satisfied its appetite. Its subterranean 

 excursions cannot cover a wide range, but 

 they enable it to visit a few adjacent cells. 

 I have mentioned how greatly the Tachytes' 

 provision of Mantes varies.^ The smaller 

 rations certainly fall to the males, which are 

 puny dwarfs compared with their compani- 

 ons; the more plentiful fall to the females. 

 The parasitic grub to which fate has al- 

 lotted the scanty masculine ration has not 

 perhaps sufficient with this share; it wants an 

 extra portion, which it can obtain by chan- 

 ging its cell. If it be favoured by chance, 

 it will eat according to the measure of 

 its hunger and will attain the full develop- 

 ment of which its race allows; if it wander 

 about without finding anything, it will fast 

 and will remain small. This would explain 

 the differences which I note in both the 

 grubs and the pseudochrysalids, differences 

 amounting in linear dimensions to a hundred 

 per cent and more. The rations, rare or 

 abundant according to the cells lit upon, 

 would determine the size of the parasite. 

 During the active period, the larva un- 



1 The essay on the Tachytes has not yet appeared in 

 English. It will form part of a volume entitled More 

 Hunting Wasps. — Translator's Note. 

 152 



