16 C. SASAKI. 



eggs would be crushed with the strong jaws of the silkworm, when the 

 leaves are chewed, but in reality this does not take place. Owing to 

 their hard chitinous covering and to their diminutive size, the eggs 

 enter uninjured and whole into the digestive canal of the silkworm. 

 That the eggs do not get hurt in passing into the body of the worm is 

 further confirmed by comparing the size of the pieces of the leaves 

 contained in the digestive canal with that of the egg. It will be found 

 that the size of the former is many times that of the latter. 



In one to nine hours after the eggs are introduced into the di- 

 gestive canal (P/, III, fig. la) of the silkworm, their shell breaks 

 open by a longitudinal slit appearing on their flat surface ( PL III, fig. 

 2), and then a young maggot hatches out into the contents of the 

 canal. It is however still enveloped by another thick transparent 

 oval sac ( vetcUine membrane, Fl. Ill, fig. 1 k ), colored light yellow. 

 This, in its turn, soon opens at one end, and the imprisoned tiny mag- 

 got (n. Ill, fig. li; fig. 2 A) now becomes free. The empty egg 

 shells and oval sacs mingling with fœces pass out later from the body 

 of the silkworm. The shells and sacs thus voided by the silkworm are 

 easily seen under a low power of microscope, by pressing ftDces on a 

 glass plate with a cover glass and by applying a few drops of water. 

 The maggot (iV. Ill, fig. 1 i) thus hatched out in the digestive canal 

 measures 0.3 and 0.2 mm. in length and breadth respectively. It is 

 colorless and transparent ; its smaller anterior end is provided with a 

 horny hooked jaw while its broader posterior end has two spiracles, 

 and each segment of the body is covered with a transverse r(5w of 

 sette. 



After remaining in the digestive canal from one to eight hours, 

 the maggot passes out through the lining wall of the canal probably 

 with the aid of its hooked jaw, and enters directly into the ganglia which 

 lie close beneath the canal, generally leaving those ganglia free ( /'/ 



