l8 9i»] Anatomical and Physiological Researches. 307 



same organization as the protoplasm. It is protoplasmic 

 fibrillar impregnated with cellulose. Certain obscure physio- 



logical problems are luminously explained under this view, 



viz., cell-growth, geotropism, ascension of sap, irritability in 

 general, heliotropism, budding, and movements, such as 

 those of amoebae, plasmodia, bacteria and the diatoms. The 

 method of M. Fayod — leaving aside the detail — is to inject 

 bits of tissue with indigo, very finely powdered and in sus- 

 pension. The preparation is dehydrated with alcohol after 

 the usual method, and is examined in clove-oil. In this way 

 it is possible to inject the spirally-twisted protoplasmic fibril- 

 lae and thus expose them for examination and study. In 

 seed-coat cells of Cuphea for example, the spirofibrillae are 

 found to have exactly the structure of a capillitium-fiber 

 from certain TricJiias — a genus of Mycctozoa. 



This distinctly original view of protoplasmic constitution 

 will, of course, need verification. It seems certain that pe- 

 culiar spirally-twisted elements may be demonstrated in pro- 

 toplasm by any one who follows Fayod's method, which is 

 not a tedious one. The writer obtained results with epidermal 

 cells from young Pelargonium leaves. 



With the space at command, it is not possible to discuss 

 fully the ingenious explanations which, under his conception 

 of protoplasm, M. Fayod offers for the various physiological 

 phenomena which present themselves to his notice. To most 

 readers of his paper, however, it is certain that no page will 

 be more interesting than the one on geotropism. Very sim- 

 ple, physical and mechanical laws suffice for the explanation 

 of this crux of plant-physiologists. By the weight of liquids 

 in the spirofibrillae, under the action of gravity, longitudinal 

 tension, in the cell-lining, is decreased and cell-formation 

 takes place more readily along the line perpendicular to the 

 surface of the earth. And the more gross materials will col- 

 lect in the lower portions of fibrillae and in the lower fibrillae, 

 leaving the finer, ethereal, easily dialysable substances upper- 

 most, thus tending to inflate upper parts of fibrillae and 

 upper fibrillae. Under such conditions of the mechanism, 

 together with the variation of environment, nutritive rhythm, 

 and changes periodic and constant in metabolic processes 

 and products, Fayod finds little difficulty in explaining very 

 clearly both geotropism and negative geotropism {zcnotropism, 

 turning toward the zenith). He quotes effectively the ex- 



