20 



HARDWICKE'S SCIENCE-GOSSIP. 



[Jan. 1, 1868. 



Jover of wild flowers will be surprised at my re- 

 collecting the circumstance even after the lapse of 

 so many years. — A. 7/"., Waltham Holy Cross. 



Edible Fungi. — In the " Journal of Botany " 

 for March, 1863, Mr. Cooke described a well, 

 marked new species of Pholiota with decurrent 

 gills, under the name of Agurcius capistratus, and 

 of which, he writes, " taste rather unpleasant ;" 

 and Mr. Berkeley, on referring to this species 

 elsewhere, says it " does not appear to be escu- 

 lent." The plant is probably rare, for it has not 

 been observed in its old London haunts since 

 1863, and I never saw it till last week, when 

 Mr. J. Aubrey Clark, of Street, Somerset, sent 

 me three fine specimens out of a batch found at 

 the foot of an elm. He did not know what the 

 plant was, but wrote me concerning it :— " The 

 smell is so mushroomy and wholesome, that I ex- 

 perimented on it today and found the flavour 

 delicious." He wrote me the next day to say he 

 had eaten largely of the species, and found it 

 excellent. I also tried the three he sent me, and have 

 no hesitation in saying they were truly delicious. 

 Now, Agaricus capistratus is closely allied to another 

 species much smaller and with aduate gills {Agaricus 

 pudicus) ; it grows near elms and elders, and is 

 generally acknowledged to be a good thing. Even 

 Mr. Berkeley, who will not subscribe to the good 

 qualities of Agaricus rubescens, writes of this plant 

 " esculent ! " Agaricus pudicus was extremely com- 

 mon tliis year about Tottenham and Waltham- 

 stow, where I gathered large quantities ; but in 

 every case the smell was so insufferably horrible 

 as to preclude the very idea of tasting it. The 

 above facts conclusively show that fungi are sub- 

 ject to some external agency whicli on certain 

 occasions, and under certain conditions, entirely 

 alters their nature. — W. G. S. 



Ivy Again. — A similar instance to that recorded 

 last month by Mr. Holland, exists at Tisbury. A 

 friend of mine there, wishing to destroy an ivy 

 plant which covered part of his house, caused the 

 stem, three inches in diameter, to be sawn through. 

 Although this was done more than three years ago, 

 the plant, as jet, shows no sign of decay, being as 

 green, and apparently as strong as ever — A. G. T.' 



MICROSCOPY. 



Snails' Tongues. — Peeling especial interest in 

 Snails' tongues, I cannot refrain from challenging 

 your correspondent (A. M. Edwards) upon one part 

 of his communication (1S67, p. 277) — I mean the 

 mountins of the tongues. As regards his method 

 of preparation, it is one whicli I, and others here, 

 have long practised with success, nor have I aught 

 to say upon this part of the matter save that even 



with the most delicate species, whilst fresh, I have 

 never found the boiling process injurious. Wheu, 

 however, Mr. Edwards recommends the soaking of 

 these tongues in turpentine, and finally mounting 

 them in balsam, I stand utterly aghast ! — knowing 

 by experience that such a course of treatment is 

 quite useless for any purpose of scientific investi- 

 gation, inasmuch as it involves two great evils — 

 first, an utter distortion and flattening of teeth 

 which lie in different planes; secondly, and yet more 

 fatal, complete obliteration of all the most delicate 

 features of an organism naturally very transparent. 

 The only satisfactory way of proceeding is to mount 

 in fluid, in a cell, with sufficient pressure to open 

 out the ribbon, but not enough to reduce everything 

 to a dead level. The fluid I find most advantageous 

 is a weak form of Goadby's Solution ; some advise 

 salt and water, others glycerine ; I object to the 

 latter as giving too great transparency, and some- 

 times interfering with sharpness of definition. The 

 use of polarized light is particularly valuable in an 

 investigation of many of these tongues, and we on 

 this side the Atlantic are at length beginning to 

 learn that it is not necessary to sacrifice our 

 specimens to Canada Balsam in order to enjoy its 

 advantages. The one great cry of microscopists 

 who use the Polariscope has always been " Give us 

 light ;" and indeed, with a Nicol prism below the 

 object, and a Nicol prism above it, this demand is 

 far from unreasonable ; but let me say most empha- 

 tically, get your light by an alteration in the 

 apparatus, not by a distortion of the object. Let 

 the polarizing prism be fitted beneath an Achroma- 

 tic Condenser, or, failing that luxury, have a simple 

 convex lens of short focus fixed above it, and allow 

 the arrangement to be fitted into a sliding 

 jacket as you would fit a spot lens or a 

 a parabola. Never again will you com- 

 plain of want of light ; never again will 

 you put a tongue into Canada Balsam. 

 And if accurate definition be wanted, or 

 examination with high powers required, 

 discard the abominable Nicol prism above 

 the objective, and use in its stead a 

 crystal of herapathite over the eyepiece. 

 With such a polarizing apparatus as this, 

 you may work as comfortably with a one- 

 eighth objective as with a two-inch. — W. 

 R. May, Islington. 



Haiks of Anthkenus. — Since publish- 

 ing figures of the hairs of Anthrenus in 

 our last volume (p. 206), we have dis- 

 covered a figure in Heeger's "Album 

 microscopisch-photographischer darstel- 

 lungen" (fig. 90) of the hairs of the larva 

 of another s]iecics,Anlhrcuus scrophularia, 

 whicli we have reproduced (fig. 10), as 

 this species has also been found in Great Britain. 



Fig. 10. 



Hair of 



Larva of 



Anthrenus 



Scrophu- 



lariae. 



