41 



HARDWICKE'S SCIENCE-GOSSIP. 



MICROSCOPY. 



Cells.— A slide with movable cover, better than 

 either of those noticed in the last two numbers of 

 Science - Gossip, is " Piper's Revolving Cover 

 Slide." It is a mahogany slide with circular open- 

 ing, and the cover is a bone disk, which is fixed to 

 the side by a brass stud, near the edge of the cell, 

 so that it can be turned on one side (as on a pivot) 

 to view the object. They may be used for any 

 opaque object, but are admirably adapted for mount- 

 ing moss capsules to exhibit the hygrometric move- 

 ments of the peristome. I have used the wooden 

 box cells mentioned in Science-Gossip, February, 

 186S, for the latter purpose, but found the moisture 

 from the breath condense upon the glass slide to 

 which the boxes were attached; and another objec- 

 tion was, that the loose lids were not of one uniform 

 size. A loose lid should be made to fit any box in- 

 discriminately ; but a revolving cover is, I think, 

 preferable. This slide was invented by Mr. Piper, 

 of the Old Change Society, and those I use were 

 bought at Baker's, in Holborn.— A. S. 



A New Mounting and Dissecting Micro- 

 scope. — I have been lately using one of Mr. Field's 

 Universal Mounting and Dissecting Microscopes in 

 the preparation of objects, and find it so useful and 

 so compact, that I think some of your readers may 

 be glad to know of its existence.— B. H. Nisbeti 

 Broicne. 



New British Desmids. — Mr. Archer has 

 recently brought before the Dublin Microscopical 

 Club examples of new and rare Desmids ; amongst 

 which we notice SpJuerozosma secedens (de By.),found 

 at Kylemore, County Galway; also a species of 

 Staurastnm allied to S. Iceve of Ralfs, of which he, 

 for the present, regards it as' a variety {Clevei). 

 A species of Euastrum has been found, which ac- 

 cords with no described species in many features, 

 but is allied to E. ansatum (Ehr.). At a succeeding 

 meeting, Mr. Archer exhibited Slaurastrum maa- 

 mense, Archer, and Micrasterias fimhriuta, Ralfs ; 

 both rare, and found in gatherings from Connemara. 

 On other occasions, the same gentleman exhibited 

 new and rare specimens of Desmids, and other 

 minute algce, and offered his opinion thereon. How 

 is it that Mr. Archer finds his perseverance so well 

 rewarded by the continual discovery of new and in- 

 teresting forms in Ireland, and that in England no 

 addition whatever is being made to our knowledge 

 of the distribution, structure, &c, of these interest- 

 ing algae ? 



Scale of Minnow {Leuclscus phoxinus). — 

 These scales are very minute and delicate ; in fact, 

 they require that the fish should be scraped with a 

 penknife, and the scrapings transferred to a little 

 water on a slide, and submitted to the microscope 



before they can be discovered. When found, the 

 character of the scale is sufficiently distinct from all 

 the others heretofore figured that it will not be con- 

 sidered too much trouble to pursue the course we 

 have indicated in order to obtain them. Our readers 

 will remember that we have already figured a con- 

 siderable number of the scales of British fresh-water 

 fishes in previous volumes. The series is not yet 

 complete ; there are several we should still like to 

 add, and for these we await with patience the co- 



Fig. '22. Scale of Minnow. 



operation of those of our correspondents who arc 

 interested in the subject. Positive accuracy in 

 identification of species is indispensable. This is 

 comparatively easy iu some cases, as that of the 

 Barbel, &c. ; but where not so easy, it is prudent to 

 submit the fish from which the scales are taken to 

 some competent authority. Under these conditions 

 we shall be glad of scales from all species not yet 

 figured in this journal. 



Structure of Insect Scales. — This subject 

 has been much discussed of late, and, of course, 

 there has been difference of opinion. In the 

 "Monthly Microscopical Journal" for January 

 appeared a paper by Mr. S. J. Mclntire, illustrated 

 by three page plates, containing numerous figures ; 

 and the eleven pages of letter-press abound with 

 observations and suggestions of interest on the 

 structure of these objects, hitherto so little compre- 

 hended or understood. 



Microscopy in New York.— We learn that 

 there are in reality two Microscopical Societies in 

 New York City. The oldest is the American 

 Microscopical Society of New York, which, for 

 some cause or other, does not seem to have realized 

 all that many ardent spirits desired; consequently 

 the Bailey Microscopical Club was established, and 

 is in such vigorous condition— so we are informed— 

 that it threatens to "go-a-head, and beat all other 

 Microscopical Clubs in the ' versal world.' " Move 

 on, brother Jonathan, and good luck to you ! 



