770 SUMMARY OF CURRENT RESEARCHES RELATING TO 



yellow, Millon's reagent red. These solutions and the presence of 

 phosphorus distinguish iiucleine from other albuminoids. 



Zacharias demonstrated these reactions in nuclei obtained from 

 the epidermal cells of Tradescantia virginica, and from the parenchyma 

 of young leaves and stems of Banunculus Lingua. If a fresh Trades- 

 cantia cell is treated with artificial gastric juice, the delicate puncta- 

 tiou of the nucleus becomes at first somewhat more distinct, its 

 volume being slightly reduced ; it then becomes completely homo- 

 geneous, and presents the appearance of a drop of oil. But it soon 

 begins to increase again rapidly in volume, loses its brightness, and 

 becomes frotliy ; and finally, without again shrinking perceptibly, has 

 a sharp outline, is frothy, yellow, and strongly refractive. As soon 

 as the nucleus increases in size and becomes homogeneous, the starch- 

 producers swell up rapidly and disappear. The protoplasm of the 

 cell becomes at the same time completely or partially frothy, the 

 bubbles being filled with a clear yellow fluid. Finally, the bubbles 

 burst, and the cell-protoplasm disappears ; the nucleus being enclosed 

 in a very delicate colourless folded pellicle, of somewhat swollen 

 appearance, the remains of the parietal layer, the threads, and the 

 nuclear disk. After longer treatment with gastric juice, this residue 

 of the protoplasm loses its swollen appearance, and forms a somewhat 

 shining pellicle round the nucleus, which undergoes no further 

 change. 



Metastasis in the Vegetable Organism.* — W. Detmer defines 

 metastasis {Sfoffwechselprocesse) as comprising those processes by 

 means of which organic compounds already present in the organism 

 are transformed into new organic comj^ouuds, or are completely 

 destroyed. The metastatic processes in the cells of j^lants may be 

 associated with the absorjjtion of oxygen and evolution of carbonic 

 acid, with the absorption of oxygen alone, with the evolution of car- 

 bonic acid alone, or finally, even with the evolution of oxygen. 

 These last can, of course, take place only in cells that contain 

 chlorophyll, and only under the influence of light, and are hence 

 liable to be confounded with processes of assimilation. But this last 

 term should, according to the author, be confined to processes which 

 take place at the expense of inorganic substances, such as carbonic 

 acid and water, resulting in the production of organic compounds. 



With regard to the process of respiration, Detmer distinguishes 

 the following four kinds : — 



1. Normal respiration. This term is apjilied to the process which 

 is connected with the absorption of oxygen and evolution of carbonic 

 acid, the volume of gas eliminated being equal to that of the gas 

 absorbed. 



2. Vinculation-respiration. This takes place in the case of the oil 

 of oily seeds in the early stages of germination, the absorption of 

 oxygen not being accompanied by any evolution of carbonic acid. 



3. Internal respiration. This process is associated with the evolu- 

 tion of carbonic acid, but not with the absorjition of free oxygen, 



* Jahrb. f. wiss. Bot., xii. (1881) pp. 237-87. 



