174 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Structure and Behaviour of Larva of Anopheles maculipennis.* 

 A. 1). I nuns gives a preliminary account of the larvae of this mosquito, 

 collected in the neighbourhood of Cambridge. The various systems in 

 the body are described. The large oenocytes are segmentally arranged 

 in clusters ; the small oenocytes, which are very numerous, have no 

 definite arrangement. The imaginal buds are well developed and easy 

 to discover. They are superficial in position, being situated just below 

 the hypodermis, and the primitive invaginations of the buds remain 

 permanently open. 



In another paper f he describes the external features, digestive and 

 respiratory systems. Perhaps the most interesting structure in the 

 digestive system is the peritrophic membrane, a thin, probably chitinous 

 tube which completely incloses the food as it passes through the mesen- 

 teron. It appears to protect the mesenteric epithelium from abrasion 

 by hard and resisting particles of food. Like other chitinous mid-gut 

 linings, it is shed at ecdysis. On the respiratory system certain tracheal 

 branches are described which are very thin-walled, and which by envelop- 

 ing the terminal chamber of the heart probably enable the blood to come 

 into close contact with their contained oxygen, and in this way form a 

 kind of " lung." Tracheal anal gills are also present, which are well 

 supplied with blood, and probably function as accessory respiratory 

 organs. 



Shell-bearing Mycetophila Larva.J — Nils Holmgren describes 

 the anatomy of the larva of Mycetophila ancyUformans sp. n. which 

 carries a black shell, and which was at first mistaken for an Ancylus. 

 It occurs on the leaves of a species of Barnbus in the primeval forests of 

 Bolivia and Peru. A diagnostic description of the imago is also given. 



Relation of Fleas to Plague Dissemination. § — Carlo Tiraboschi 

 gives a very full discussion of this subject, bringing together all the 

 known facts regarding the role of rats and mice, their distribution, and 

 the morphology of their fleas. The paper also contains a systematic 

 account of the families Pulicidse and Sarcopsyllidge, together with 

 notes on the Pediculi and Acarid parasites of the rat. Rats and mice 

 play an important part in disseminating plague ; it is quite established 

 that fleas are disseminated from rat to rat, from rat to man, and from 

 man to man. The fleas concerned in plague dissemination are Pulex 

 cheopis Roth., Ceratophyllus fasciatus Bosc, Ctenopsylla musculi Duges, 

 Ctenocephalus felis Bouche, and Ctenocephalus canis Curtis ; the most 

 probable species in transference from rat to man are P. cheopis, 

 P. irritans, Ctenocephalus felis, C. canis, and, perhaps, Ceratophyllus 

 fasciata, but chiefly P. cheopis. This last-named species is widely dis- 

 tributed on rats in the plague-infested regions of India and Australia. 

 The facility with which it is transported naturally by man in the absence 

 of rats renders it very important. Neither the Sarcopsyllidaa, lice, nor 

 Acarids are of significance in this connection, and bugs ordinarily do 

 not play an important role in the dissemination of plague. 



* Proc. Cambridge Phil. Soc, xiv. (1907) pp. 292-5. 



t Journ. Hygiene, vii. (1907) pp. 291-318 (2 pis. and 1 fig.). 



t Zeitschr. Wiss. Zool., lxixviii. (1907) pp. 1-77 (5 pis. and 2 figs.). 



§ Arch, de Parasitol., xi. (1907) pp. 545-620 (15 figs.). 



