ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 579 



to those which invest the calices ; the prolongations which they give off 

 are grouped into bundles which make their way among the olfactory glome- 

 ruli, and are lost in the central dotted substance of the lobe. In the 

 pedicle there are fibres and dotted substance ; the antennary nerve is com- 

 posed of two bundles. The tritocerebrum, unlike what happens in some 

 insects, notably the Orthoptera, is fused with the neighbouring parts, and 

 can only be distinguished by the point of origin of the common trunk of the 

 nerve for the labrum and the stomatogastric nerve. 



Life-history of Ugimya sericaria.* — Prof. C. Sasaki gives an account 

 of the life-history of Ugimya sericaria, the Dipteron whose larva plays 

 terrible havoc among the silk-worms which are raised in Japan in May and 

 July. After describing the external and internal anatomy of the adult fly, 

 in which particular attention is given to the structure of the generative 

 organs, the development of the maggot is considered ; the greater number 

 of eggs are laid in May, and deposited on mulberry bushes, with the 

 leaves of which they are eaten by the silkworm ; owing to their small size 

 and hard chitinous covering they are not crushed by the strong jaws of the 

 silkworm, and pass uninjured into the digestive tract. In one to nine 

 hours the shell breaks open by a longitudinal slit on its flat surface ; the 

 escaped maggot is invested in a thick transparent oval sac, which soon opens 

 at one end, when the tiny creature becomes free. After one to eight hours 

 the maggot, probably by the aid of its hooked jaw, passes through the wall 

 of the canal and enters directly into the ganglia which lie close beneath ; 

 ordinarily the silkworm is now weakened, and its body presents an unusual 

 aspect from the severe irritation of the nervous system. The appearance 

 produced may be understood from the popular name of " swelled segment " 

 which is given to the disease. Feeding on the ganglion-cells the parasite 

 grows larger and larger ; after about a week it passes into the body and 

 " directly searches for the portions of the tracheal system of its host where 

 the stigmata open." Here it forms a sort of cup by heaping up the fats 

 and muscular fibres of its host round the opening made on entering, and 

 sticking them together with its saliva ; it now feeds entirely on fat. The 

 presence of a dark brown or blackish patch round the stigma is conclusive 

 evidence of the presence of the parasite. In addition to the disease 

 mentioned, other diseases and symptoms may be caused by the presence of 

 the maggot. 



When it reaches maturity the maggot leaves its abode in the body of the 

 silkworm or its pupa, and, making a hole in any part of the body of its host, 

 it passes into the cocoon, and thence to the outer world. The author describes 

 in detail the habits and anatomy of the mature maggot, the structure of the 

 pupa, and its developement into the mature insect, and concludes a very 

 interesting essay by some suggestions as to the protective methods which 

 should be adopted. It is interesting to note that the pupa of this fly is 

 itself infested by a parasitic mite, which probably belongs to the genus 

 Tyroglyphus. 



Pedigree Moth-breeding.f — In order to obtain new data for verifying 

 certain important constants in the general theory of heredity, Mr. Francis 

 Galton proposes to experiment on moths, more especially on those which 

 are double-brooded. He points out the advantages, such as the short lives, 

 no change in length of wing, and ease of rearing and preserving, &c., to be 

 obtained by using moths as subjects. 



It is intended to start from a brood of a single pair of moths, and to 



* Journ. College of Science, Imp. Univ. Japan, i. (1886) pp. 1-46 (6 pis.). 

 t Trans. Entom. Soc. Lond., 1887, pp. 19-28. 



