THE ENTOMOLOGIST. 89 



split bamboos or flexible rods are placed so as to form a 

 slight arch over the trajs, dry twigs are loosely spread over 

 the arches and the larvae are placed on them to spin their 

 cocoons. In the course of ten days the twigs are firmly 

 connected by the silk, and they are then hung from the 

 ceiling until the cocoons are removed. This is a brief 

 account of the rearing of the larvae, as gathered from Mr. 

 Adams's Report; and anyone who may desire to learn more 

 — for there is a careful account of the mode of winding the 

 silk, from which much may be learnt — I would refer to the 

 Report. 



And now I would turn to the errors in this Report on the 

 most important subject of a parasite (called uji) which infests 

 B. Mori. The importance of the subject may be imagined 

 when it is stated that in some districts the number of pupae 

 found to be killed by this parasite is eighty-four in a 

 hundred. The name uji signifies maggot, and the larva of 

 this parasite is described as " annulated and without feet." 

 The spring brood of silk larvae are alone affected, the 

 summer brood escaping. The uji when full-grown eats its 

 way from the silk cocoon (which is spoiled except for floss 

 silk), and " changes from pale yellow to reddish brown, 

 gradually becoming darker and darker, and it shrinks up to 

 a third of its size. After three or four days it becomes quite 

 hard and nearly black." From the above description of the 

 parasitic larva, and the changes which it undergoes after 

 emerging from the silk cocoon (which is whilst turning to 

 pupa), I think this must be a dipterous insect. When it has 

 thus shrunk and turned nearly black, it is supposed to be 

 dead. The dry uplands of the interior are less infested by 

 the uji than the low damp localities, or the districts bordering 

 on the sea. To quote from the Report : — " One theory, which 

 appears to be the true one, and has been held by several 

 foreigners, is, that during the spring a species of fly deposits 

 its eggs on the mulberry-leaf, and that these eggs, being 

 introduced with the leaf into the silkworm's intestines, turn 

 into uji after the worms have arrived at the chrysalis state." 

 That this theory, both as to the introduction of the egg and 

 the feeding of the parasitic larva, is not the correct one, may, 

 I think, easily be proved. If the egg were introduced into 

 the larva in this way, and only hatched in the silk pupa, the 



