ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 267 



of the intcrnodes, the leaf-stalks and mid-rib of the leaves, the 

 rhizome, and the roots. Observation of the currents leads to the 

 conclusion that it is by these currents that the substance for the 

 formation of starch is conveyed to the amyloplasts. 



For the purpose of these observations the author placed a large 

 drop of a 5 per cent, solution of sugar on the substance to be cut, 

 moistening the knife also with the same solution. Each section was 

 then placed on the slide, the sugar solution removed by blotting- 

 paper and replaced by a new drop. The sections were then left for 

 from one to two hours before examination, by which time the currents 

 of protoplasm had again set up. 



Chemistry of Chlorophyll.* — Mr. E. Schunck first deals with the 

 action of acids on chlorophyll ; the best to use is hydrochloric acid. 

 By adopting essentially the method of Fremy he had been able to 

 separate phyllocyanin and phylloxanthin. The properties of the 

 former are described in detail ; when heated on platinum it gives off 

 an acid smell, swells up considerably, evolving gas which burns with 

 a smoky flame, and leaves a voluminous charcoal which burns away 

 slowly, leaving hardly a visible trace of ash. It is rapidly decom- 

 posed on being treated with boiling dilute nitric acid. Insolation 

 causes it to yield products which resemble, if they are not identical 

 with those due to the action of nitric and chromic acids. Phyllo- 

 cyanin appears to play the part of a weak base, that is, it combines 

 with strong acids, the compounds, however, being unstable and easily 

 decomposed, even by water. Mr. Schunck enumerates a number of 

 the compounds he was able to obtain, among which are phyllocyanin 

 cupric acetate, stearate, and phosphate, phyllocyanin zinc palmitate 

 and oleate, phyllocyanin ferrous citrate and malate ; the characters of 

 these various compounds are described. 



Studies on Chlorophyll.t— M. V. Jodin describes some experi- 

 ments bearing on M. Eegnard's hypothesis, that the action of chloro- 

 phyll on carbonic acid is purely chemical, and not physiological. In 

 order to prove this he suppresses in turn all the physiological condi- 

 tions. After being dried, the green leaf loses the power of decom- 

 posing carbonic acid and exhaling oxygen in sunlight. By leaving 

 a leaf for sixty-five hoiu's in an atmosphere of hydi-ogen or of nitrogen, 

 it likewise loses this power. He suppressed the respiration of the 

 leaves by heating them in sealed tubes in a water-bath. Some of the 

 tubes were then placed in the dark, and were found to have under- 

 gone no change ; but others, placed in sunlight, became discoloured, 

 by absorbing the oxygen in the tubes. 



This result seems to show that, " apart from the physiological 

 entirety, light only acts on the leaf by destroying chlorophyll and 

 giving rise to oxidation." In order to show that this photochemical 

 oxidation was really exerted on the chlorophyll, and not on other 

 substances, such as tannin, a solution of xanthophyll, &c., in alcohol 

 was placed in sunlight, when it was found to become oxidized and 



* Proc. Roy. Soc, xxxix. (1885) pp. 348-61. 

 t Comptes Rcndus, cii. (1886) pp. 264-7. 



