THE EYE OF PEOTEN. 55 



were stained in Delafield's liaematoxylin and washed well in 

 tap water. This was followed by staining for five minutes in 

 a mixture of — 



1 per cent, solution (aqueous) saurefuchsin . 5*0 

 Saturated solution of picric acid in water . lOO'O 



The stained sections were washed in tap-water and taken 

 up to balsam as usual. 



Carnoy^s fixative was used in the following strength : 

 Chloroform ...... 10*0 



Acetic acid ...... oO'O 



Absolute alcohol ..... 60*0 



This is the best fixative for the retina. Iron hsematoxylin 

 and Bethe's toluidin blue were the stains used on material 

 so fixed. 



Bouin's fluid ('Lee/ edit, vi., p. 76) gave excellent results 

 for rod-cells and rods, especially when followed by Mallory's 

 stain. The axial fibre of the rods was stained better by the 

 saurefuchsin in this method than by any other except the 

 modified Weigert. Zenker's fluid, Mann's fluid/ and a mix- 

 ture of equal parts of corrosive sublimate satui-ated aqueous 

 solution, and Hermann's platinum-osmic fluid were useful for 

 the lens, especially the latter. 



Other fixatives used were 4 per cent, formol, corrosive 

 sublimate (aqueous solution and solution in salt water), 

 Mayer's pici-onitric mixture ('Lee and Mayer,' ed. vi, p. 68), 

 Flemming, Von Ratli's picro-platinum-osmic mixture, and 

 treatment with pyroligneous acid. The latter did not give 

 particularly good results. There were also special fixing and 

 other processes connected with the following methods — Grolgi's 

 silver process (Cajal's modification), Bielschowsky-Paton silver 

 method for neurofibrillse (41), Apathy's nachvergoldung and 

 hgematein I A methods, Nabias' gold method. Lists' eosin 

 method, and methylene blue processes. The latter were 

 failures, though injection methods, staining in aqueous solu- 

 tions, solutions in Pecten serum, and dusting powder over the 

 eye were all tried. The results given by the other and more 

 1 Mann, ' Physiological Histology,' p. 96 (solution d). 



