1883.] 



MICROSCOPICAL JOURNAL. 



131 



cida in England, seenis to be with the 

 vertical illuminator, and that is used 

 so as to throw a line of light into the 

 field just covering and illuminating 

 the diatom, leaving the rest of the 

 field dark. This is done by taking 

 the light directly from the edge of the 

 flame, without interposing a con- 

 densing lens between the flame and 

 the illuminating reflector. 



When Mr. Nelson suggested to cut 

 away sections of the screw-threads of 

 the objective and nose-piece so as to 

 quickly attach and detach the former, 

 we felt very doubtful if the plan 

 would be regarded with favor by mi- 

 croscopists generallv. Ourdoubts have 

 been fully confirmed by what we have 

 seen. Nevertheless, the plan is a 

 most excellent one, and the best evi- 

 dence we can offer of our faith in its 

 value, is that we propose adopting it 

 ourselves as soon- as we can obtain 

 the templates, or a copy of them. 

 The ingenious " facility nose-piece " 

 devised by Mr. Pease, of Massachu- 

 setts, which we have had the pleasure 

 of first exhibiting in London, has been 

 received with great favor. This in- 

 strument, and also the new camera 

 lucida of Mr. Grunow, with some ex- 

 cellent objectives by Messrs. H. R. 

 Spencer & Co., a ^ and a -jVinch, 

 " professional " series, were shown by 

 us at a meeting of the Royal Micro- 

 scopical Society. 



The international fisheries exhibi- 

 tion was opened in London on the 

 i2th of May, and we are pleased to 

 say that the exhibit of the United 

 States, in charge of Commission- 

 er G. Brown Goode, and his able 

 assistants, is a most creditable 

 one, and in many respects more 

 complete than any of the others. 

 There is a fine collection of slides 

 from Mr. Potts, of Philadelphia, il- 

 lustrative of the fresh-water sponges ; 

 some beautifully mounted specimens 

 of algae from Prof. Farlow, and a few 

 embryological specimens entered by 

 the writer. In the British section 

 Mr. Thomas Bolton has arranged 

 some fresh and salt-water aquaria 



with living microscopic specimens, 

 sponges, polyzoa, hydroids, infusoria, 

 and various other objects, which he 

 exhibits and explains with the aid of 

 several microscopes. There may be 

 much more of interest to microscop- 

 ists in the exhibition, but it is too 

 early to learn just what is to be seen, 

 for there is yet much to be done be- 

 fore the collections are all properly 

 displayed. 



At a recent meeting of the Quekett 

 Microscopical Club, at which, how- 

 ever, we were only able to be 

 present for a few moments, we saw a 

 few living specimens of the recently 

 discovered fresh-water medusa Cras- 

 pedactistes Sowcrbeyii or Limtioco- 

 dium Victoria. It was discovered in 

 the Victoria regia tank at Kew Gar- 

 dens, where it has been found in con- 

 siderable abundance. 



At a meeting of the Royal Micro- 

 scopical Society Mr. Crisp an- 

 nounced that Mr. J. D. Miiller has 

 prepared a type-slide of 1600 diatoms, 

 which any person can obtain for 

 about $400.00. 



At the same meeting Mr. W. Wat- 

 son exhibited a new microscope, which 

 he acknowledged to be a copy of Mr. 

 Bulloch's "biological" stand. 



Mr. G. E. Davis has shown us some 

 very fine photographs of microscopic 

 objects, designed to be used with the 

 lantern for projecting upon a screen. 

 One was of a FIeurosig??m angulatnm, 

 which was far more perfect than we 

 supposed it would be possible to ob- 

 tain from the object. In fact it 

 leaves nothing whatever to be desired, 

 and the dots are as clearly defined in 

 the transparency as they are seen in 

 the microscope. 



Another fine plate shows the Vol- 

 vox globator, as natural as life. This 

 slide was made by Dr. Maddox. How 

 he killed the plant, and caused the 

 the balls to retain their form and po- 

 sition we do not know, but doubtless 

 osmic acid was used, and perhaps 

 some staining fluid. We would not 

 have supposed that such a good lan- 

 tern-slide of Volvox could be made 



