The Microscope, 117 



lutions the preparation was left for at least 24 hours. It was after- 

 wards immersed in a mixture of 2 parts of ordinary spirit and 1 part 

 of water. The direction of the sections was meridional, transverse 

 and tangential. For staining, Bohmer's haematoxylin and eosin were 

 exclusively used. The logwood solution was several months old, and 

 very weak. This device prevented the celloidin fi'om becoming 

 stained. Dr. W. B. Canfield, (Ibid.) in his researches on the accom- 

 modation apparatus of the bird's eye, employed Semper and Fred- 

 ericq's method for dry preparation, and also the celloidin process. 

 The eyes were fixed in Muller's fluid, and then hardened in spirit. 

 For decalcification, saturated solution of picric and chromic acid, and 

 nitric acid 2 per cent, were used. The eyes were then embedded in 

 celloidin by Czermak's method, and the sections, stained with haema- 

 toxylin and eosin, were mounted in balsam. In elucidating the 

 structure, of moUuscan and arthropod eyes {Mt. Zool, Stat. Neapel, 

 vi 1886). Mr. W. Patten notes the satisfactoiy results obtained by 

 the following methods : When sections were not resorted to, the 

 tissues were hardened a very little and then macerated. The use of 

 chromic acid has to be vai'ied in strength and temperature, etc., for 

 different regions: it was found especially iTseful to shift in half an 

 hour from a one-tenth per cent, to a one-twentieth, in 24 hours back 

 again to one-tenth, in 24 hours to a one-fifth, where it was kept for 

 48 to 60 hours. The cornea was best treated with picro-chromic, the 

 lens with picro-sulphuric, the layer of nerve-fibres below the septum 

 with one-fifth per cent, chromic acid for 24 hours, the retinophorae 

 with chromic, the rods and the retinidia with one-fifth per cent, 

 chromic at 50 degrees C. for half an hour. The best preparations, 

 with all the parts in the most natiu-al position, were obtained by kill- 

 ing the eyes first with one-tenth per cent, chromic acid for half an 

 hour, allowing them to remain in one-half per cent, for 24 hours, 

 one-tenth per cent, for 23 hours, and finally one-fifth per cent, for 48 

 hours or more. — Journal R. M. Society. 



RosANiLiN Nitrate for Goblet and Mucus Cells. — Dr. J. H. 

 List (Zeitschr, /., Wiss., Mikr, iii. 1886), now uses a 0.0001 per 

 cent, of rosanilin nitrate for goblet and mucus cells. Sections taken 

 from 50 per cent, alcohol are overstained in the above fluid for ten 

 to fifteen minutes. The superfluous stain is then extracted in 

 absolute alcohol. The nuclear structure, as well as the reticulum of 

 the cell, are vvell shown. After hardening in chrom-osmium- acetic 

 acid, the chromatin of the nucleus comes out extremely well. The 

 Karyokinetic figures in epithelium are also well shown. — Journal 

 R. M. Society. 



