ZOOLOGY AND BOTANY, MICROSCOPY, KTC. 453 



of this much-studied nucleus, and emphasizes the fact that the chromatin- 

 fchread forms a spiral closely coiled on itself. This structure, described 

 by some as cross-striation, seems to be permanent in Ohironomus, and 

 the author believes that this is no unique case. 



Flies and Typhus Fever.* — B. Bertarelli submits experimental 

 evidence showing that house-flies may serve as disseminators of typhus- 

 fever. 



Head and Mouth-parts of Dipterous Larvae .f — E. Becker has made 

 a welcome contribution to our knowledge of the mouth-parts of dipterous 

 larvae. He deals with Encephala {Ohironomus, Simulia, Sciara), Poly- 

 neura (Tipula, Pedicia), Orthorrhapha brachycera (Atherix, Stratiomys), 

 and Cyclorrhapha (Musca, Anthomyia). The interpretation of the re- 

 duced head of a Muscid larva is briefly discussed. 



Adaptations of Parasitic Diptera.J — J. Pantel discusses the manner 

 of exploiting the host in Sarcophagidas, Conopidas, Tachinidse. He 

 describes parasitism in ganglia and in muscles, and various reactions on 

 the part of the host. Castration by parasites is discussed, and the struggle 

 of parasite with parasite. The author compares different life-cycles in 

 the families studied. The influence of the host on the parasite is also 

 discussed. But we cannot do more than indicate the general scope of 

 this investigation. 



Structure, Habits and Life-history of Candle Fly.§ — J. C. W. Ker- 

 shaw gives an account of Pyrops candelana, and GL W. Kirkaldy furnishes 

 some additional notes. The snout is not luminous, as has been some- 

 times asserted, but the food-reservoir extends to the tip of it. The male 

 is a long time courting the female, and is jealous of another's attentions. 

 All day long he stretches out and vibrates the hind leg on the side 

 nearest the female and sways his body from side to side. They appear 

 to couple only at night. The eggs are laid in straight rows on a trunk 

 or branch, thinly covered with colleterial fluid, and brushed over with 

 white waxy matter. They hatch in about twenty-six days, and the nymphs 

 can run and jump soon after their emergence. They sit in long and 

 fairly ordered rows, very cryptic in form and colour. When nearing 

 their fifth moult they have a slight secretion of wax on the abdomen. 

 The wax of Pyrops is formed in bundles or masses of thread or fibres ; 

 it collects largely over the spiracles and in the wax-pockets ; more than 

 one kind of parasite, or rather, perhaps, inquiline, lives in it and feeds 

 on it, e.g. a minute mite, not so large as this full-stop. An interesting 

 account is given of the internal structure, particularly of the alimentary 

 system. 



Post-antennary Organ of Collembola.|| — E. Becker gives an account 

 of the structure of this organ in Poduridse, Entomobryidre, and ttmin- 

 thuridaj. In all cases the sensory cells of the organ are internal to the 

 epidermis, and they are innervated from the protocerebrum, and, except 



* Centralbl. Bakt. Parasitenk., liii. (1910) pp. 486-95. 



t Zool. Jahrb., xxix. (1910) pp. 281-314 (3 pis. and 5 figs.). 



t La Cellule, xxvi. (1910) pp. 27-216 (5 pis. and 26 figs.). 



§ Zool. Jahrb., xxix. (1910) pp. 105-24 (3 pis.). 



|| Zeitschr. wiss. Zool. xciv. (1910) pp. 327-99 (2 pis.). 



