14 C. SASAKI. 



compouixl eyes, aiul the remaining pair ( t? (^ ) lie;? in the proLotcis^. 

 All these air-sacs communicate with one another by air-tubes, Avhilc 

 the tubes sent posteriorly from the air-sacs marked c, c put those of the 

 head in conmiunication with the air-sacs in the thorax and abdomen. 

 The two pairs of air-sacs in the thorax (e e\ ff) open directly into the 

 spiracles on its lateral side, and the single pair of sacs in the abdomen 

 {(I il) "which occupy the greater portion of its cavity open into the spiracle 

 of only the first and second segments by means of air-tubes (P/. 7, /î'r/. 

 10). The air-tubes arising from the spiracles on the third abdominal 

 segment have their ends attached to the tubercles resting on the "rectal- 

 tasche," while those arising from the spiracles on the fourth, fifth, and 

 sixth segments have most of their branches distributed on the vagina 

 {VI. II, fig. 3 c). 



AVith regard to tlie nervous system ( VI. II, fig. 13 ) it will be found 

 that the arrangements of the ganglia ( Supra-and infra-œsuphageal and 

 optic ) in tlie head are very similar to those of the pupa of Musca vom. 

 studied by A. Weismann, bat there are two thoracic ganglia which are 

 connected with each other by two commissures. From the posterior 

 one of these ganglia there are given out again two long commissures, 

 each of which, passing into the abdomen, bifurcates into two at its 

 free end. 



III. 



Development of the Maggot. 



As I have stated before, the fiies deposit eggs during May and 

 June, and the greater portion of them towards the end of May, this be- 

 nvx about the time when the silkworm attains the third or fourth staofe 



