BKATJLINA. 419 



erally. While the transformations of Braula show it to be 

 undoubtedly a degraded Muscid, with a true puparium ; those 

 of the flea, with its worm-like, more highly organized larva, 

 and the free obtected pupa show that, though wingless, it 

 occupies a much higher grade in the dipterous series. Braula 

 coeca Nitzsch (Fig. 343, and larva) is found living parasitically 

 on the honey bee in Europe, and has not been detected in this 

 country. 



The antennae are short, two-jointed and sunken in deep 

 pits. It is from one-half to two- thirds of a line long. The 

 larva is headless, oval, eleven-jointed and white in color. On 

 the day it hatches from the egg it sheds its skin and changes 

 to an oval puparium of a dark brown color. It is a body para- 

 site, one or two of them occurring on the body of the bee, 

 though sometimes they greatly multiply and are very trouble- 

 some to the bee. 



Fig. 344. 



We now take up the second series of suborders of the hexa- 

 podous insects, in which the different segments of the body 

 show a strong tendency to remain equal in size, as in the larva 

 state ; in other words there is less concentration of the parts 

 towards the head. In all these groups the prothorax is greatly 

 developed, generally free, while the wings tend to conceal the 

 two posterior thoracic segments, and the body generally is 

 elongated, flattened or angulated, not cylindrical as is usually 

 the case in the preceding and higher series. The degraded 

 wingless forms resemble the worm-like Myriapods, while, as we 

 have seen above, the wingless flies resemble the Arachnida. 

 The imago (especially in the Hemiptera, Orthoptera and cer- 

 tain Neuroptera) resembles the larva ; that is, the metamor- 

 phosis is less complete than in the preceding groups. 



