HARBWICKE'S SCIENCE-GOSSIP. 



135 



MICROSCOPY. 



EUGLENA VIRIDIS.— I have much pleasure in being 

 able to acquaint you with the fact that I have again 

 been fortunate enough to observe all the phenomena 

 pertaining to the Euglcna viridis, to which I drew 

 your attention last year ; viz. bulbous termination of 

 the flagellum, contractile vacuole, etc. This seems ; 

 to me the more"_ important, as the organisms have j 

 been drawn from a different locality from any of ; 

 those examined last year. In many cases, the bulb j 

 is more fully developed in this year's growth than in 

 those of last year, which permits it to be seen with 

 a less powerful combination than was necessary in 

 previous' cases. I enclose sketch (drawn by means 

 of the camera lucida) showing the organism as seen 

 through a Beck \ inch, with No. 2 eyepiece (giving 

 an enlargement of 360 diam.). The stunted appear- 

 ance results from the animal being partially contracted 

 when killed by a solution of iodine. — F. Jas. George. 



I 



MoyNTiNG Starches. — The method recom- i 

 mended by A, J. D. in a recent number is not a good 

 one. Heat alters the form of all starches. When 

 required for polariscope objects, thin dammar and \ 

 thin balsam are perhaps the best media, used cold ; 

 and left to harden spontaneously. By this process \ 

 wheat starch and many others which do not polarise 

 under ordinary circumstances, show well. For ' 

 ordinary examination I find a weak solution of 

 ammonia one of the best media, — Ediijard Hunter. 



New Zoophyte Trough. — Mr. J. Campbell 

 Christie, of Hamilton, N.B., is rather behind the 

 times in his discovery of the new zoophyte trough he 

 writes about in your issue for I^Iay. The trough he 

 describes was invented seven years ago by Mr. C. 

 Botterill, of Liverpool, one of the most active and 

 successful members of the microscopical society of 

 this city, and bears his name. I believe that the first 

 were made in vulcanite, but experience showed that 

 that substance was not stiff enough to give an equal 

 pressure when screwed down, and Mr. Botterill 

 improved upon his first invention by substituting 

 brass for the vulcanite, and in this improved form 

 they, may now be had of Mr. J. C. Thompson 

 (Thompson & Capper), Lord Street, Liverpool, Hon. 

 Sec. of the Microscopical Society, also of Mr. J. J. 

 Marr, optician, Mooifields, Liverpool. I have seen 

 many notices of this invention, the credit of which 

 has been given to one or another, but not to Mr. 

 Botterill. Some claim it as their own, and others 

 ascribe it to American ingenuity ; but this and 

 several other things, adding to the convenient mani- 

 pulation of the microscope, are the result of his ex- 

 perience and ingenuity, and to him belongs the 

 honour. The cost of the brass trough, I think, is 

 3J-. each. — John J. Hoxvdl. 



Parasites on Hydra. — On the loth of April I 

 obtained some weed from a pond on Ealing Common, 

 and amongst it I subsequently found a few fine speci- 

 mens of Hydra vulgaris. About a week afterwards, 

 when looking at one of them through a pocket lens, 

 I observed that it was infested by minute parasites (?) 

 and accordingly I brought the fact and the specimens 

 before the members of the West London Scientific 

 Association at their next meeting (April 26), but no 

 one present was able to give me any information on 

 the. subject ; nor could I, either then or subsequently, 

 find any mention of such in any book whatsoever. 

 Two days afterwards I received my copy of Science- 

 Gossip, and was glad to see that some one else was 

 in difficulties as to what these infusoria might be. 

 To the accuracy of J. O. B.'s general description of 

 these little creatures I can fully testify. Unfortu- 

 nately my specimens perished before I could find the 

 time to fully investigate them ; but as far as I could 

 make out, their lateral aspect very closely resembled 

 that of Stichotricha sccunda, figured in Pritcliard's 

 "Infusoria" (3rd edit. i£6i, pi, xxviii. fig. 43); 

 whilst seen from above they appeared of an oval 

 shape, and most like the dorsal view of Kcrona 

 mytilus, figured in the " Micrographic Dictionary" 

 (3rd edit. 1875, pi. xxiv. fig. 27). When detached 

 from the Hydra they progressed at a fair rate through 

 the water, rotating the while. Like J. O. B. I 

 watched them for a long time, but could not see that 

 they did anything but glide over the body of the 

 Hydra, or venture occasionally on to the tentacles ; 

 still, I have a kind of feeling that they bode no good 

 to their host, and think they must have received 

 notice of the approaching dissolution of the Hydra, 

 or why, of two Hydras stationed within half an inch 

 of each other, should one be infested and the other 

 not ?— ^. B. IF. 



Insects and Primroses. — My attention having 

 been attracted this season by the large number of a 

 minute insect (a species I believe of Thysanoptera) 

 frequenting the corolla of Primroses, I was led to 

 examine a number of the flowers attacked by the 

 insects, and ascertained the following facts, from 

 which it would appear that they play a not unimpor- 

 tant part in the self-fertilisation of those flowers of the 

 primrose not already cross-fertilised, i. The insects 

 in question are to be found almost exclusively on the 

 short-styled form. 2. They feed only on the stamens 

 or the portion of the corolla immediately adjacent to 

 them, and never seem to eat any portion of the pistil. 

 3. By their nibbling at the stamens, the pollen and 

 occasionally an anther itself, is loosened and falls to 

 the bottom of the tube, i. e. towards the stigma, which 

 in its descent it can scarcely fail to fertilise. But for 

 this insect agency the narrowness of the tube (which 

 is increased by the anthers themselves blocking it up) 

 would be a great preventive to self-fertiUs-ition, In 

 the long- styled form since the stamens are situated 



