18 



THE AMERICAN MONTHLY 



[January 



5. Antenna of moth. B.B.Grif- 

 fith. 



6. Transverse section of diseased 

 human colon. Geo. M. Kreider. 

 This is a very excellent preparation 

 for the Club, because it is well de- 

 scribed with a drawing to indicate 

 what is to be seen, and the signifi- 

 cance of the appearances. The Club 

 wants more of this kind of work. 



NOTES. 



— We are indebted to Mr. Nereus Bald- 

 win for some interesting photo-micro- 

 graphs which he has made. One is a 

 photograph of a portion of the wing ot a 

 butterfly taken with a binocular micro- 

 scope and the prints mounted for a stereo- 

 scope. This is very well done. The 

 specimens of most interest, however, 

 show the lines on Amphipleura in vary- 

 ing degrees of clearness. In one we 

 have nearly the entire frustule on a print 

 about seven inches in length, ' showing 

 longitudinal lines.' The frustule was 

 mounted in Prof. Smith's new medium, 

 and photographed with a Spencer -^^ 

 homogene immersion. The lines, how- 

 ever, are evidently diffraction or spurious 

 lines. Another picture shows the trans- 

 verse lines faintly, but as it was made 

 from a Moller test-plate in balsam by 

 lamp-light reflected from the mirror, it 

 is a very creditable result both for the 

 operator and the Spencer lens. The last 

 picture is an excellent one of the lines of 

 a broken frustule nrounted in Prof. Smith's 

 medium. The lines are very distinct, 

 and show excellent skill in both the mi- 

 croscopical and photographic work. 



— A correspondent desires to know the 

 best method of preserving urinary casts. 

 The subject is not well treated in the 

 hand-books of microscopy, and we can 

 only reply with some hesitancy, owing 

 to our limited experience. The best re- 

 sults we have had in mounting tube-casts 

 were with dilute carbolic acid for a me- 

 dium, using shellac as the cement. The 

 casts kept very well for a year or more, 

 but the preparations are not now in our 

 cabinet. Perhaps some reader will give 

 his experience in this direction for the 

 benefit of others. 



— Somebody has suggested that it would 

 be well to mention some attractive and in- 

 structive objects for mounting, as an aid 



to those who have not good opportunities 

 to see many fine objects. Perhaps some 

 useful hints will be found in the account 

 given below of an exhibit of preparations 

 at a recent meeting of the San Francisco 

 Microscopical Society : ' The first series 

 was illustrative of the structure of spiders, 

 and the various characteristics by which 

 this interesting group of Arachnida is 

 separated from insects were well shown 

 by the preparations under examination. 

 The comb-hke foot by means of which the 

 spider weaves and traverses its wonderful 

 web, the powerful jaws through which it 

 injects a virulent poison into its hapless 

 victim, the marvelous group of organs 

 termed spinnerets, wherein is formed the 

 viscid secretion which is finally formed 

 into a thread and spun into a web, and 

 finally the brilliant eyes of the jumping 

 spider, were all carefully examined, and 

 their peculiarities of structure pointed out, 

 many novel and interesting facts being 

 thus elicited. The jaws of the garden 

 spider, Epcira diadcma, were displayed 

 under polarized light, and the resulting 

 play of colors was very beautiful. But 

 the inost effective preparation of the entire 

 lot was one of the brilliant eyes of the large 

 jumping spider, Saliicus iardigradtis, 

 mounted by F. Enock, a prominent Eng- 

 lish entomologist. The eyes of all spiders 

 are simple, not compound as in the case 

 of insects, and this forms one of the rea- 

 sons for separating them from the latter 

 group. In the hunting or jumping spiders, 

 the eyes are especially large and very 

 brilliant. They are set in a straight row 

 across the forehead, the two largest in the 

 centre, and all gleam with a weird play of 

 color that gives an appearance of peculiar 

 ferocity to the head.' 



— The Palmer Slide Company offers 

 thin glass for sale in sheets, squares, or 

 circles, the thickness being guaranteed 

 between certain limits. This is a matter 

 of considerable importance, especially to 

 those who use high power lenses. For 

 those who are studying bacteria it is very 

 desirable that very thin and very uniform 

 covers should be available. Perhaps some 

 specially selected covers would be offered 

 by the Company for this work, should the 

 demand for them arise. 



— Messrs. Cassino & Co. have reprinted 

 the Spencer-Harrison controversy con- 

 cerning the origin and reality of religion, 

 the book which was issued by Messrs. 

 Appleton & Co., but the entire edition de- 

 stroyed at Mr. Spencer's request. It may 

 fairly be inferred that the present is a 



