CHAPTER XLI* 



AXIS-CYLINDER AND DENDRITE STAINS (GOLGI AND 



OTHERS) 



1025. Introduction. There are three chief methods for the 

 anatomical (§ 977) study of axis-cyhnders and nerve-cell pro- 

 cesses, viz., the methylen blue intra-vitam method, the bichromate 

 and nitrate of silver, and the bichromate and sublimate inethods 

 of GoLGi. The methylen blue method has already been described 

 in Chapter XVIII. (§§ 376 et seq.), and only a few points remain to 

 be dealt with here. These, together with some other methods 

 suitable for similar purposes, will be given at the end of this 

 chapter, the principal object of which is the description of the 

 GoLGi methods. 



1026. The Methods of Golgi. There are two methods of 

 Golgi, viz., the Bichromate and Nitrate of Silver Method and the 

 Corrosive Sublimate Method. 



The bichromate and nitrate of silver method has been worked 

 out by Golgi in three forms — the slow process, the rapid process, 

 and the mixed process. 



The rapid process is the one mostly used at the present time, 

 and it may be regarded as the classical method of inquiry into 

 the general morphology and distribution of nerve-cells and their 

 processes in hardened tissues. One must, however, remember 

 that extremely delicate results may be obtained by both the 

 mixed process and the corrosive sublimate method, and that 

 use should be made of them also, particularly for the study of the 

 finer relations of the nervous elements. 



General Characters of the Impregnation. The preparations have 

 not in the least the appearance of the usual stains, and are even 

 very different in aspect from those obtained by the ordinary 

 methods of impregnating with silver or gold. The impregnation 

 is a partial one, by which is meant that of all the elements, whether 

 nervous or not, that are present in a preparation, only some are 

 coloured. This is one of the great advantages of the method, for, 

 if all the elements present were coloured equally, one would 

 hardly be able to follow any one of them for more than a very 

 short distance. Golgi's method selects from among the elements 

 present a small number which it stains with great intensity and 

 very completely ; that is to say, they are very clearly separated 



* Revised and in great part re-written by C. D. F. 



. 490 



