176 FABBE'S BOOK OF INSECTS 



arrive it shrivels, and casts its skin ; and it is then that the 

 pupa appears, fully clad in a stout, reddish, horny hide. 



The head is round and large, and is crowned on top and 

 in front with a sort of diadem of six hard, sharp, black spikes, 

 arranged in a semi-circle. This sixfold ploughshare is the 

 chief digging - implement. Lower down the instrument is 

 finished off with a separate group of two small black spikes, 

 placed close together. 



Four segments in the middle of the body are armed on the 

 back with a belt of little horny arches, set in the skin upside 

 down. They are arranged parallel to one another, and are 

 finished at both ends with a hard, black point. The belt 

 forms a double row of little thorns, with a hollow in between. 

 There are about two hundred spikes on the four segments. 

 The use of this rasp, or grater, is obvious : it helps the pupa 

 to steady itself on the wall of the gallery as the work proceeds. 

 Thus anchored on a host of points the brave pioneer is able to 

 hit the obstacle harder with its crown of awls. Moreover, to 

 make it more difficult for the instrument to recoil, there are 

 long, stiff bristles, pointing backwards, scattered here and 

 there among the rows of spikes. There are some also on other 

 segments, and on the sides they are arranged in clusters. Two 

 more belts of thorns, less powerful than the others, and a sheaf 

 of eight spikes at the tip of the body two of which are longer 

 than the rest completes the strange boring- machine that 

 prepares an outlet for the feeble Anthrax. 



About the end of May the colouring of the pupa alters, and 

 shows that the transformation is close at hand. The head 

 and fore-part of the creature become a handsome, shiny black, 

 prophetic of the black livery worn by the coming insect. I 

 was anxious to see the boring-tools in action, and, since this 

 could not be done in natural conditions, I confined the Anthrax 

 in a glass tube, between two thick stoppers of sorghum-pith. 

 The space between the stoppers was about the same size as 

 the Bee's cell, and the partitions, though not so strong as the 

 Bee's masonry, were firm enough to withstand considerable 



