ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 37 



and rapid river in Fiji. " Myriads of black specks were seen dancing 

 on the surface of the water. When alarmed, they hid behind stones. 

 They skated on the water, or jumped to a height of about six inches, 

 usually several times in close succession, and were sometimes seen to 

 leap upon very disturbed water. Now and then three or four of the 

 crickets seemed to be playing at leap-frog, and jumping over one 

 another, as if in sport. They were very hard to catch, though several 

 men were employed in capturing them, and very few specimens were 

 secured." 



The largest male was 11 mm. long, not including the antennse, cerci, 

 or wing-tips. The female insect differs most conspicuously from the 

 male in the presence of a rather long, curved ovipositor, and in the 

 quite different pattern of the wing-cover. It seems necessary to recog- 

 nise the genus as distinct, and as belonging to the tribe Trigonididse, 

 among which it is distinguished by the male elytron being partly mem- 

 branous and altogether unlike that of the female, but without functional 

 stridulating organ, while the hind tibia bears two series of articulated 

 spines. 



Spermatogenesis of LocustidaB.* — C. E. McClung describes in 

 detail the spermatocyte divisions in Xiphidium, Orchesticus, Anabrus, 

 and other Locustidas. We quote the tenth and last paragraph of his 

 summary. " From each first spermatocyte there are formed, by two 

 divisions, four spermatids, of which two are distinguished from the re- 

 maining pair by the possession of an extra chromosome in addition to 

 the number — sixteen — common to them all. Both classes undergo a 

 like series of transformations by which they become mature spermatozoa. 

 These are necessarily of two kinds ; and it is believed that those con- 

 taining the accessory chromosome, in the act of fertilising the egg, 

 determine that the germ-cells of the embryo shall be sexually male, or 

 like themselves, while those from which it is absent are unable to 

 impress their sex upon the egg and assist in producing female embryos." 

 We have here another contribution to the interesting subject of sperma- 

 tozoic dimorphism. 



Development of Nervous System in Muscidse.j — K. Escherich 

 gives a full account of the development of the nervous system in Lucilia, 

 with especial reference to the so-called "median strand " (Mittelstrang). 

 He finds in the ventral cord two genetically distinct systems : — the 

 paired lateral nerves and unpaired median nerve. They arise indepen- 

 dently and are only secondarily associated. As Heymons has discovered 

 a dorsal nerve in Scolopendroids, the author suggests that the Urform 

 of the nervous system in Arthropods may have consisted of four longi- 

 tudinal strands. 



Species of Mosquitos concerned in Diffusion of Malaria.J — A. 

 Bordi concludes from his own studies and those of others, that in the 

 greater part of Europe malaria is diffused by Anopheles claviger F. (or 

 0. maculipennis Mei.), and to a small extent by A. bifurcatus L. ; that 



* Kansas Univ. Sci. Bull., i. No. 8 (1902) pp. 185-231 (4 pis.), 

 t Zeitschr. f. wiss. Zoo!., Ixsi. (1902) pp. 525-49 (I pi). 

 X Rend. R. Accad. Lincei Roma, xi. (1902) pp. 318-24. 



