SPECIAL METHODS. 



205 



a. Protein Crystalloids. 



359. The protein crystalloids observed in the chromato- 

 phores, especially by Schimper (III) and A. Meyer (II), often 

 form elongated prisms (cf. Fig. 41, 2) or needles (Fig. 41, i 

 and Fig. 39, I,/) ; but they are not rarely more octahedral 

 or more or less irregular (cf. Fig. 41, i, 3, and 4). 



With the exception of those of 

 Canna, they are soluble in water, 

 but are fixed by fixing media for 

 proteids. I have found the same 

 methods used for the study of the 

 nuclear crystalloids (cf. 345 to 

 347) well suited to their investi- 

 gation. Fixing with an alcoholic 

 solution of corrosive sublimate 

 and staining with acid fuchsin by 

 method C has proved the best 

 treatment. In this way it is 

 pretty easy to obtain prepara- 

 tions in which the stroma of the 

 chromatophores is quite colorless, 

 while the cr)-stalloids are colored deep red 



FIG. 41. r, leucoplasts from a young 

 shoot of Canna Warszewiczii with 

 crystalline needles and octahedral 

 crystals; 2, chloroplasts from the 

 epidermis of the petiole of Hedera sp.; 

 3, chloroplasts from the palisade-pa- 

 renchyma of the leaf of Convolvulus 

 tricolor; 4, chloroplasts from the 

 palisade-parenchyma of the leaf of 

 Achyranthes Verschaffelti ; , pro- 

 tein crystalloids; j, starch-grains, 

 i, after Schimper. 



b. Leucosomes. 



360. Within the leucoplasts of the epidermis of various 

 species of Tradescantia, and in various other plants, I have 

 found globular inclusions which I have provisionally termed 

 leucosomes (cf. Zimmermann II, 3 and III, 147). These 

 consist, at least chiefly, of protein-like substance and are 

 probably closely related chemically to the protein crystal- 

 loids already described, with which they also correspond in 

 their behavior with acid fuchsin. 



In favorable cases, as, for instance, in the epidermis of the 

 leaves of Tradescantia discolor, the leucosomes may be well 

 observed within the living cell, and tangential sections are 

 especially adapted to this study. They occur here mostly 



