SPECIAL METHODS. 



195 



the ovary-wall of Campanula trache- 

 lium. 2, nucleus from the spongy 

 parenchyma of the leaf of Melam- 

 pyrum arvense. 3, nucleus from the 

 epidermis of the leaf of Lophospermum 

 scandens. 4, nuclei from the palisade- 

 parenchyma of the leaf of Candollea 

 adnata. 5, nuclei from the wall of an 

 almost ripe fruit of Alectorolophus 

 major. 6, nuclei from the ovary of 

 Mimulus Tilling!, n, nucleolus. />, 

 protein crystalloids. 



Mimulus Tillingi (Fig. 34, 6), or variously curved forms, as 



in the wall of the ovary of 



Campanula tr ache Hum (Fig. 



34, i). Finally, bodies of the 



same chemical relations are 



widely distributed, which vary 



little or none from the globular 



form, as for example in the leaf 



of Lophospermum scandens (Fig. 



34, 3). In such cases the certain 



proof Of their Crystalloid nature, FIG. 34-1, nuclei from thT^idermi. of 



and especially the distinction 



between them and the nucleoli, 



is not possible by the simple 



examination of living material. 



But this distinction may be 



-easily and certainly made by the 



aid of suitable staining methods. These leave any doubt only 



as to whether all those bodies which correspond with the 



undoubted crystalloids are really to be regarded as identical 



with them in substance ; but it may be considered as certain 



that these are not identical with any other known inclusions 



of the nucleus. 



For the recognition of crystalloids one may best fix the 

 material with a concentrated alcoholic solution of corrosive 

 sublimate ( 310) and stain with acid fuchsin, or use a double 

 staining of acid fuchsin and haematoxylin. As to the stain- 

 ing with acid fuchsin, which is also known as " Fuchsin S 

 after Weigert," this may be conducted in various ways ; but 

 the three following methods have proved best heretofore 

 (cf. Zimmermann II, 12 and 55, and III, 113). 



a. Altmann's Acid Fuchsin Staining. 



345. This is chiefly useful for microtome sections. These 

 are fastened to. the slide and, after the removal of the par- 

 affine, are covered with a solution of 20 grams of acid fuch- 

 sin in 100 ccm. of aniline-water,* and then warmed until the 



* This solution keeps well and only needs to be filtered occasionally. 



