Larval Dimorphism 



walls of the nest ? Failing to make their en- 

 trance at the proper time, they no longer find 

 viands to suit them. The primary larva of 

 the Sitaris continues from the autumn to the 

 following spring. Even so the initial form of 

 the Anthrax might well continue, not in in- 

 activity, but in stubborn attempts to overcome 

 the thick bulwark. 



My young worms, when transferred with 

 their provisions into tubes, remained stationary, 

 on the average, for a couple of weeks. At last, 

 I saw them shrink and then rid themselves of 

 their epidermis and become the grub which I 

 was so anxiously expecting as the final reply to 

 all my doubts. It was indeed, from the first, 

 the grub of the Anthrax, the cream-coloured 

 cylinder with the little button of a head, fol- 

 lowed by a hump. Applying its cupping-glass 

 to the Mason-bee, the worm, without delay, 

 began its meal, which lasts another fortnight. 

 The reader knows the rest. 



Before taking leave of the animalcule, let 

 us devote a few lines to its instinct. It has 

 just awakened to life under the fierce kisses 

 of the sun. The bare stone is its cradle, the 

 rough clay its welcomer, as it makes its en- 

 trance into the world, a poor thread of 

 scarce-cohering albumen. But safety lies 



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