282 SUMMARY OF CURRENT RESEARCHES RELATING TO 



of green fruit and the air or water in the bottle, the latter two 

 usually varying one way Or the other by about a degree ; a difference 

 of a degree was also recorded between the two extremities of the 

 fruit, which represent different stages of growth. This is suggestive 

 of an interesting line of research. 



Respiration of Leaves in the Dark.* — Experiments were under- 

 taken by MM. P. P. Deherain and L. Maquenne to ascertain whether 

 any of the carbonic acid produced by green leaves was retained by 

 them. A known quantity of the leaves of Euonymus japonica was 

 placed in a known volume of pure air ; this air was then analysed. 

 The leaves were then placed in vacuo, when the remainder of the air 

 retained by the leaves was extracted and analysed. The relation 

 between the "apparent ratio" (first result) to the "real ratio" (both 

 results together) was found to depend on the ratio of the volume of 

 the leaves to the volume of space in which they were confined. 

 Leaves placed in an atmosphere of carbonic acid, in the dark, absorb 

 a considerable quantity of the gas. 



Intramolecular Respiration.f — Herr W. Pfeffer has tested the 



conclusions on this subject of Mr. W. P. Wilson by the method of 



passing alternately a current of air and of hydrogen over plants, and 



absorbing by baryta-water the carbonic acid produced. Designating 



the carbonic acid produced by normal respiration, by N, and that 



N 

 produced by intramolecular by I, then the proportion ^ differs for 



different plants, though almost always less than unity ; Vicia Faha 

 being the only plant in which it approached unity. With seedlings 

 of Sinapis alba it was 0*177; with Abies excelsa, 0*077; with leafy 

 shoots of Ligustrum vulgare, 0*816; with beer-yeast, 0*31; with 

 Cantharellus ciharius, 0*666. Intramolecular respiration is not a 

 phenomenon of decadence, but is connected with the vitality of the 

 cells. The author regards respiration as a true process of direct 

 oxidation. 



Respiration of Plants. | — Pursuing their researches on this sub- 

 ject, MM. G. Bonnier and L. Mangin confirm their previous conclu- 

 sions that at any given moment for the same individual the relation 



C 



— Y^ is independent of temperature, pressure, and light, equally for 



all kinds of plants and for all parts of the plant. They now find, in 

 Pinus maritimus, the same results at all temperatures between zero 

 and 36° C, and in the ivy between zero and 35° C. These conclu- 

 sions are also now confirmed by the results obtained by MM. 

 Deherain and Maquenne.§ 



* Comptes Kendus, ci. (1885) pp. 887-9. Cf. this Journal, v. (1885) p. 678, 

 t Unters. aus d. Bot. Inst. Tubingen, i, (1885) 50 pp. (1 fig.). See Bot. 

 Centralbl., xxiv. (1885) p. 161, 



X Comptes Kendus, ci. (1885) pp. 1173-5. Cf. this Journal, v. (1885) p. 835. 

 § See this Journal, v. (1885) p. 678. 



