ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 159 



7. Myriopoda. 



British Symphyla.* — R. S. Bagnall makes a report on the distri- 

 bution of British Symphyla, for a knowledge of which we are mainly 

 indebted to himself. He deals with five species of Scutigerella (five of 

 which he discovered), and nine species of Scolopendrella (five of which 

 he discovered). 



e. Crustacea. 



Life-cycle of Moina rectirostris.j — Geoffrey Smith reports on the 

 experimental observations made by the late Gr. H. Grosvenor and him- 

 self. According to Weismann, in the life-cycle of Moina sexual forms 

 should be produced in every parthenogenetic generation independently 

 of external conditions. But it was found that by isolating the partheno- 

 genetic females at birth until the production of the brood, at a tempera- 

 ture of 25°-30° C, the production of sexual forms is entirely suppressed, 

 1167 parthenogenetic females and no sexual forms having been obtained 

 by this means. 



Parallel cultures with related females crowded together in the cul- 

 ture-glasses at a temperature of 25°-30° C, gave 30 "3 p.c. males, 

 and at about 14° C. gave 52*3 p.c. males. Isolated females at 1-4° C. 

 gave 10*1 p.c. males. Isolated females in an ice-chest at about 5° C, 

 gave 5 '4 p.c. males, when crowded together 42*5 p.c. 



The intensity of crowding, measured by the number of parents kept 

 together in the same glass, is shown to have a not very constant effect 

 on the proportions of males produced ; on the whole the proportion of 

 males increasing with the intensity of crowding. The influence of 

 isolation and of a high temperature on the suppression of the sexual 

 forms may be ascribed either to the comparative absence of excretory 

 matter under these conditions, or else to the nutritive conditions being 

 highly favourable. 



Blood of Hermit-crab.:|: — J. Cantacuzene finds that the blood of 

 Eupagurus prideauxii has a strong hsemolytic effect on the red blood - 

 corpuscles of Mammals, and a strong power of agglutinating Bacterium 

 coli, etc., e.g. in the gills. It has also a slight precipitating effect on the 

 serum of the horse and the rabbit. The hermit-crab in question lives 

 inside the shell of Trochus, and is accompanied by the sea-anemone, 

 Adamsia palliata, and it is a remarkable fact that the haemolytic, 

 agglutinating, and precipitating qualities of its blood are not found in 

 those of a neighbour species, Pagurus striatus, which lives in association 

 with the sponge Suherites domuncida. 



Herpyllobius arcticus.§— Kathleen Haddon describes this parasitic 

 Copepod, which is remarkable for the extreme degeneration of the adult 

 male and female, both of which are entirely devoid of appendages. The 



* Trans. Nat. Hist. Soc. Northumberland, Durham, and Newcastle-upon- 

 Tyne, iv. (1912) pp. 171-6 (1 fig.). 



t Quart. Journ. Micr. Sci., Iviii. (1913) j)p. 511-22. 



X C.R. Soc. Biol. Paris, Ixxiii. (1912) pp. 663-4. 



^ Quart. Journ. Micr. Sci., Iviii. (1912) pp. 385-410 (1 pi. and 4 figs.). 



