44 



HA RD WICKE ' S S CIENCE- G SSIP. 



zoology, botany, and microscopy, has ' ' A Revision of 

 the Qgxm.'s, Aiiliscus, Ehrb., and some Allied Genera," 

 by John Rattray ; and also a " Note on the Large 

 Size of the Spicules of Acis orientalis," by F. Jeffrey 

 Bell. 



Celloidin. — Some reader (I forgot the name), 

 three months ago asked for information about 

 Celloidin. The following is from the " Microtomist's 

 Vade Mecum," by A. B. Lee :— Celloidin is a pre- 

 paration of pure pyroxylin, patented for Germany and 

 England, under the name of " Schering's Celloidin." 

 It is manufactured by the Chemische Fabrik auf 

 Actien (vorm. E. Schering), Berlin, N. Fenstrasse, 

 II, 12. It may be obtained through the post by 

 writing to Schering's Griine Apotheke, Wiltick and 

 Benkendorf, Berlin, N. Chaussee-Strasse, No. 19. 

 •' The tablets cost three marks (three shillings) 

 each. A single tablet would, I think, suffice for im- 

 bedding many hundreds of embryos." If the above 

 is not what you want, write again, and I will give 

 any information in my power. 



I SHOULD be much obliged if any one would tell me 

 how to prepare a coffee-bean for section, cutting in a 

 Rivet-Leyser microtome. Dr. Marsh says to soak 

 them in water till soft, but I found that they begun 

 to germinate long before they were soft enough for 

 section-cutting. Can any one tell me the price of 

 the Cambridge Rocking Microtome, where it is to be 

 got, and whether it works well, also the price of the 

 Thoma Microtome ? — M. J. 



Enock's Entomological Slides. — We have 

 received two most useful and instructive preparations 

 byW. F. Enock, illustrating the "life-history" of 

 the Hessian Fly {Cccidoniyia destructor). The eggs are 

 shown in silk on the leaf of barley, and the larvre in 

 the skin. We may add that Mr. Enock has just 

 presented to the British Museum, South Kensington, 

 nineteen specimens (mounted dry) illustrative of the 

 various stages and appearances of infested barley and 

 wheat, which are placed in the new gallery devoted 

 to economic entomology. 



Microscopical Society of Calcutta. — This 

 flourishing society has issued " Keys," for the use of 

 members, to the Desmids, Diatoms, Fresh-water 

 Algae, and some Genera of Infusoria. These " keys " 

 are all printed on one sheet, and at the bottom are 

 the initials W. J. S. 



ZOOLOGY. 



ECDYSIS. — I take this opportunity of thanking Mr. 

 James Harvey for so kindly affording the information 

 contained in his paper on " The Ecdysis of Insects," 

 which appears in the October number of Science- 

 Gossip received by last mail. Mr. Harvey's paper 

 serves a double purpose : it places on record a practical 



drawing and note of his observations on PedicuJus 

 capitis, and it enables me to associate his observa- 

 tions, and mine (on Phthirius inguinalis) with Mr. 

 S. J. M'Intire's on a " Spider's Foot," which I have 

 lately found recorded in Science-Gossip, Vol. V. 

 (1869), p. 136. — W. J. Simmotis, Calcutta. 



The British Mollusca, — Having recently ex- 

 amined a copy of the " Shell-Collectors' Handbook," 

 by J. W. Williams, I may perhaps be permitted to 

 offer a few remarks concerning the descriptions given 

 of certain varieties therein, for the benefit of those 

 who have the book. Limncca stagnalis, var. eleganttda 

 (p. 78), to the description given of this may be added : 

 " Shell much smaller than type, animal tinged with 

 orange," The variety figured on p. 79 (Fig. 9), 

 appears to have no name, but it may be called var. 

 compressa, a name 1 gave it in MS. long ago. Arion 

 ate}-, several described varieties might be added to 

 the list given, and also szx. fasciata, v. nov., a variety 

 with bands resembling A. subfuscus, which I described 

 (but did not name) in the " Zoologist," from Ireland 

 some time ago. Limax agrestis, some varieties might 

 be added, including var. grisca, v. nov., entirely dark 

 greyish, which I found in Lancashire and recorded in 

 " Naturalist," 1888, p. 55. Limax arborum, var. 

 *'■ dicipiens''' (p. 92), should be decipiens. Helix 

 aspcrsa var. seniifusca (p. 108), for "third whorl," 

 read " third band." The dark variety of the animal 

 II, aspersa, which I called nigrescens, may be changed 

 to nigricans, because there is already a var. nigrescens 

 of the shell. Helix hortensis,\zx. roseozonata (p. ill), 

 the description should be : " Shell pale or whitish, 

 with rose-coloured bands." The description given on 

 p. 1 1 1 belongs to var. rufozonaia. It is probably best 

 to keep the varietal name albina for the white shells 

 of H. hortcnsis, and use subalbida for those which are 

 very pale yellow, almost white. — T. D. A. Cockerell, 

 West Cliff, Colorado. 



Love-Darts in Snails. — I should be glad if Dr. 

 J. W, Williams, or any of your correspondents, will 

 inform me whether the dart or spiculum amoris is 

 present in Helix throughout the year, or only in the 

 breeding season. I ask this because I have lately 

 been experimenting on hybernating specimens of 

 //. aspersa, and have failed in every case to find 

 anything approaching " a sharp calcareous " dart as 

 Morgan describes it. — C. A. W. 



Trout Cijlture. — The Howietoun Fishery in 

 issuing the price list for season 1888-89, records one 

 of the coldest summers experienced since the com- 

 mencement of the Fishery. Yearlings are fully three 

 weeks later than usual. The rearing season, how- 

 ever, has been exceptionally successful, and fully one 

 hundred and fifty thousand yearlings and twenty-five 

 thousand two-year-olds are ready for delivery. A 

 salmon hatched from ova obtained from the Forth 

 District Board in December, 1880, and reared in the 

 ponds, having spawned three seasons, was found in 



