ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 907 



sensitiveness to the alkaline and neutral fluids must be set the 

 persistence of Fungi, Infusoria, Dipterous larv^, and Copepoda, in 

 lakes in E. California containing almost 2^ per cent, of carbonate of 



Contradictory results having been obtained as to the action of 

 veratrin by previous observers, the authors tested it by leaving fila- 

 ments of Algae for twelve hours in the weak solution obtained by 

 boiling in water, and found the protoplasm still able to react strongly ; 

 the same result followed the substitution of -^^ per cent, solution of 

 acetate of quinine (" chinin ") ; in both cases the protoplasm, when 

 stained black, manifested remarkable disarrangement. The presence 

 of aldehydes in living protoplasm appears to be further indicated by 

 the separation of the metals by it from the dilute solutions of gold and 

 platinum chloride respectively ; the reaction with the platinum salt 

 was slight ; no reduction occurred with alkaline solutions of lead and 

 copper salts. Leaving Zygnema and Spirogyra, the authors experi- 

 mented on other plants. Cladophora, in spite of the abundance of 

 chlorophyll in its cells, separated the silver in granules which were 

 generally distributed over the cell. The Moulds yielded uncertain, 

 the Schizomycetes unfavourable results ; the Diatomaceae occasion- 

 ally precipitated the silver at certain points : these failures were pro- 

 bably due to the slight penetrability of the cell-walls of the organisms. 

 Hairs of plants were found almost as susceptible as the Zygnema 

 filaments ; those of the leaf-stalk of Alsophila australis, after twelve 

 hours' treatment with the silver solution, were found stained deeply 

 in the middle cells, faintly in those of the base and apex ; the colour was 

 almost equally distributed within the cells as .a rule, but in some 

 cases it occurred most abundantly at their ends, and gradually dimi- 

 nished in amount from thence to the centre. Good results were 

 obtained with the hairs of the corolla of Primula, and the stinging 

 hairs of TJrtica ; in the latter the deepest staining took place at the 

 apex of the hair. 



To test the behaviour of the protoplasm of the highly organized 

 vegetable tissues, roots and stems of Phanerogams were talien. Seed- 

 lings of Helianthus annuus were kept for twelve hours immersed 

 almost up to the cotyledons in silver solution; the root became 

 blackened up to this point, but especially deeply at the apex. Split 

 seeds of the same plant which had not germinated, showed, after 

 similar treatment, the presence of the silver in the cells adjacent to 

 the line of section, which appears to show the presence of aldehydes 

 in protoplasm during its resting condition. Blossoming twigs of Salix 

 caprcea and Gornus mascula, and twigs of Syringa vulgaris with bursting 

 leaf-buds, after being covered with the solution for about half their 

 height, were found blackened on the cut surface ; the colour extended to 

 almost all those cells in the branch which contained protoplasm. 

 Of animals. Infusoria were found to reduce silver in a few instances. 

 From the possession of this property of reducing silver by living, as 

 opposed to dead protoplasm, the authors explain life to be produced 

 by the molecules which cause the reaction, and describe these 

 molecules provisionally as " Aldehyde groups." 



