ZOOLOGY AND BOTANY, MICROSCOPY. ETC. 461 



a half this layer may be removed with a spatula from the subjacent yolk, 

 and should then be spread out in a flat glass containing a very small 

 quantity of picrosulphuric acid. This last should next be replaced by 

 alcohol of from 70° to 90°. Boracic carmine and alcohol are good for 

 staining advanced embryos ; Kleinenberg's hrematoxylin gives excellent 

 results in the study of karyokinesis. Saflfranin was used also as a 

 control staining fluid. 



Examining Ants for Intestinal Parasitic Infusoria.* — ^Mr. J. W. 

 Simmons cuts off the abdomen of the insect, places it in a drop of dis- 

 tilled water, and teases. Cochran's crimson ink is recommended for 

 staining the organisms, but any carmine ink would probably answer the 

 purpose. Eosein is also useful. Osmic acid is employed for killing 

 and fixing the Infusoria. 



Mounting Fungi.j — The Eev. J. E. Vizc writes that as to the 

 medium in which the microscopic forms are to be mounted, he had 

 worked at the Microscope for thirty-five years, and cannot tell yet, nor 

 does he think the man is born who can tell, which is the best mounting 

 medium. What suits one fungus does not necessarily suit another. 

 Canada balsam contracts the spores and is apt to contort them. Glycerin 

 pure and simple simply refuses in course of time to remain in the cell 

 of the slide, and works its way out. Glycerin jelly is nearly as bad, 

 and, in common with gelatin medium, contracts and expands with the 

 temperature of the weather, and therefore is unreliable. Thwaite's fluid, 

 like water, may be very successful for a time, but will be sure to change 

 the colour of the tissue eventually. Camphor water and the other 

 media which have been used in the vain attempt of beautifully balancing 

 themselves, so as to check either the growth or decay of the plant, all 

 fail. If any one asks him what media he should now use, and recommend 

 others to use, his answer would be — for any fungi that would bear them 

 (and they are not numerous), employ Canada balsam. First take the 

 greatest possible care to keep the spores in their natural place by giving 

 them as small a quantity, not of pure spirits of wine, which scatters 

 them, but benzol, which has a different effect. Let the benzol evaporate, 

 then mount. When Canada balsam will not suit, as is generally the 

 case, he uses gelatin, warming all the materials used. Water is, to the 

 best of his knowledge, indispensable when you want to see such portions 

 of a fungus as the zoospores. Much advantage may be gained by putting 

 on the label of the slide not only the name of the object, but the medium 

 in which the same is mounted. He has slides in his cabinet of great 

 scarcity, which it would be next to impossible to replace. Some of them 

 have lost the whole of the medium in which they are placed through 

 evaporation, and are almost valueless. Others have, not gone so badly, 

 but there are large bubbles of air in them, which are the forerunners of 

 total evaporation. Had the original mounter of the same named the 

 fluid in which they are placed on the slide, there would have been little 

 difficulty in bringing them back to their primitive condition. 



Fixing of the Spores of Hymenomycetes.J — Dr. C. O. Harz finds 

 that coloured spores of Hymenomycetous Fungi can be very well fixed 



* The Microscope, ix. (1889) p. 88. 



t Provincial Med. Journ., 1888, November. Cf. The Microscope, ix. (1889) 

 pp. 91-2. 



X SB. Bot. Ver. Miinchen, December 10, 1888. See Bot. Centralbl., xxxvii. 

 (1889) p. 77. 



