ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 651 



on the germination of seeds. He also finds that this acid arrests tho 

 germination, hut on its removal germination takes place to an extent 

 almost equal to what it would be if they had only been treated with 

 pure water. He also adds that hydrogen sulphide and mercuric 

 chloride arrest germination, but when the solution is very dilute 

 (0*5 per 1000) 60 to 80 per cent, of the seeds still germinate. 



Formation of Amides during the germination of seeds in the 

 dark.*— Herren B. Schulze and E. Flechsig find that when the 

 seeds of leguminous plants or cereals germinate in the dark, the con- 

 version of albuminoids into asparagin and its congeners is very 

 gradual ; and that it also varies considerably, leguminous plants, and 

 especially lupines, producing, not only absolutely but also relatively, 

 larger quantities of amides than cereals do. Seeds, when germinating, 

 do not of necessity produce an amount of amides at all proportional 

 to their nitrogenous reserve-matter. 



Absorption of Light by the Assimilating Organs.j — Herr J. 

 Keinke has made a series of photometric observations on the absorp- 

 , tion of light by the assimilating organs in a variety of plants, in- 

 cluding a number of flowering plants, green, brown, and red seaweeds. 

 For the colouring matter of the two latter classes, contained in tho 

 living active chromatophore, he proposes the terms pliseophjll and 

 rhodophyll respectively. 



The author suggests that the colourless albuminous constituent of 

 the chromatophores acts like a ferment in enabling the chlorophyll 

 to decompose the compound C0 3 H 2 with evolution of oxygen when- 

 ever the atoms of the albuminoid are set in motion by light with 

 sufficiently large vibrations. When the body of tho cell and the 

 chromatophore die, the molecule of chlorophyll breaks up into its 

 colourless and coloured group of atoms. The coloured constituent is 

 soluble in alcohol, and either breaks up by dissolution into a green 

 and a yellow constituent, or this separation exists previously. Phteo- 

 phyll and rhodophyll consist each in the same way of an albuminoid 

 and a coloured constituent. In the former case the coloured con- 

 stituent is very nearly related to the coloured group of atoms in the 

 molecule of chlorophyll. 



In the coloured constituent of rhodophyll two groups of atoms 

 can easily be distinguished, one of them agreeing, in its light-absorp- 

 tion and solubility in alcohol, with the green constituent of chlorophyll, 

 while the other absorbs most strongly the green rays which the 

 chlorophyll allows to pass through most completely, and is insoluble 

 in alcohol, but soluble in water. This group of atoms is characterized 

 by an orange-red fluorescence on the death of the chromatophore. 



Development and Absorption of Heat by Plants.! — M. G. 

 Bonnier finds that the quantities of heat developed in a unit of time by 



* Landw. Versuchs.-Stat., 1885, pp. 137-49. See Journ. Chem. Soc. Lond. 

 — Abstr., 1. (1886) p. 90. 



t Bot. Ztg., xliv. (1886) pp. 161-71, 177-88, 193-200, 209-18, 225-32, 241-8 

 (1 pi.). 



% Comptes Rendus, cii. (1886) pp. 448-50. 



