ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 997 



C4) Clieinical Changes (including Respiration and Fermentation^. 



Function of the Colouring Matter of CMoropliyll.* — Prof. A. 

 Hansen states, that like the colouring matter of blood, the absorption- 

 bands of chlorophyll have no connection with the assimilative power of 

 the same. The colouring matter absorbs carbonic anhydride, and forms 

 with it an unstable compound, which passes on the carbonic anhydride 

 to the plasma of the chlorophyll-grains. Chlorophyllous cells absorb 

 more and more gas as the temperature rises, consequently the law of 

 diffusion and absorption of gases is not followed in this case ; but the 

 absorption is dependent on atmospheric pressure. 



Biastase-t — Herr J. Fankhauser states that during the germination 

 of barley, the development of the plumule is accompanied by the 

 destruction and solution of the cell-walls in the grain. This solution 

 may be due either to a substance formed by the embryo, namely diastase, 

 or to micro-organisms. A microscopical examination, however, failed 

 to show the presence of the latter. 



Experiments showed that during the germination both of potatoes 

 and of barley, the evolution of carbonic anhydride is accompanied by 

 the secretion of one or of several powerful acids. Malt treated with 

 5 per cent, solution of potash yielded an extract, which, after suitable 

 treatment, gave a distillate, in which formic acid was the chief con- 

 stituent. It was found that both this distillate, and also commercial 

 formic acid, had the power of changing a carbohydrate into sugar. 



The author believes that the cell-walls of the starch-granules which 

 are in direct contact with the plumule are attacked by the formic acid it 

 secretes, and that in the course of brewing, the formic acid acts on the 

 starch just as dilute sulphuric acid would. He also attributes the 

 sweetness that potatoes acquire to a similar cause ; formic and probably 

 other allied acids, are formed during the respiratory process that ac- 

 companies sprouting, and these acids attack the cell-walls and also 

 change the starch into sugar. Many other phenomena of plant growth 

 can be explained by this secretion of strong acids by organs containing 

 no chlorophyll, for instance, the piercing of wood by the mycelia of 

 fungi. 



Substance containing Sulphur in Cruciferous Plants.ij: — Mr. J. 



Smith states that in the animal body the substances which contain 

 sulphur are, with one exception, exclusively proteid. or derived from 

 proteids. In plants, on the other hand, numerous sulphur-containing 

 substances are found. The amount of uncombined and of combined 

 sulphuric acid was estimated in the seeds of nineteen varieties of 

 Crucifers ; the former occurs either not at all, or in mere traces, except 

 in Isatis tinctoria, and here it is probably in the shell of the seed. The 

 ethereal hydrogen sulphates were found abundantly in all, but especially 

 in the seeds of Sinapis nigra. In this form of mustard seed, about one- 

 third of the total sulphur is combined as proteid, the remaining two- 

 thirds as myronic acid. 



* Bied. Centr., 1888, pp. 357-8. See Journ. Chem. Soc, 1888, Abstr., p. 867. 

 t Bied. Centr., 1888, pp 205-7. See Journ. Chem. Soc, 1888, Abstr., p. 867. 

 t Zeitschr. Physiol. Chem., xii. pp. 419-33. See Journ. Chem. Soc, 1888, Abstr., 

 p. 869. 



