246 SUMMARY OF CURRENT RESEARCHES RELATING TO 



appear on tho sides and bottom of the vessel, which are dark green by 

 reflected, brown by transmitted light. These crystals may be purified 

 by repeated washing in cold alcohol and then with distilled water, and 

 dissolved in ether. They dissolve with great difficulty in cold, easily in 

 hot alcohol, and immediately in ether and chloroform. The ethereal 

 and alcoholic solutions absorb tho light of the spectrum between Fraun- 

 hofer's lines B and C. This is crystallized chlorophyll (Hoppe-Seyler's 

 chlorophyllan). When its alcoholic solution is shaken with an equal 

 quantity of pure benzin, it divides into an upper green layer, the chloro- 

 phyll of green leaves, and a lower yellow layer of xanthophyll. 



The author then describes the method of obtaining other substances 

 which are associated with chlorophyll, and discusses their composition. 



Presence of active Albumin in the Cell-sap.* — Herren 0. Loew and 

 T. Bokorny state that they have discovered this substance in the cell-sap 

 of several species of Spirogyra, e. g. S. maxima. If the living plant is 

 treated with a 1 per cent, solution of a neutral salt of ammonium or of 

 an organic base, granules are at once separated from the cell-sap which 

 have a very powerful reducing effect on very dilute alkaline silver-solu- 

 tion, and give tho ordinary reactions of albumen. They consist of active 

 albumin, and appear at the same time in tho parietal utricle ; the latter 

 remain fixed at the moment of their formation, while those separated 

 from the cell-sap move about freely, and finally settle on the lower side 

 of the cell. Neither kind of granule is formed if the cell is first killed 

 by pressure ; their separation is a function of life. 



The authors adduce reasons against Pfeffer's hypothesis that these 

 particles consist of tannate of albumen held in solution in the cell-sap 

 by an acid ; the cell-sap has not an acid reaction. 



Fibrosin, a new cell-content, j — Herr W. Zopf describes a hitherto 

 unknown substance which he finds in the conidia of PodospJisera oxya- 

 canthse ; also in Spliserotheca and Erysiphe. It occurs as distinct bodies 

 of various forms, imbedded in the protoplasm, never in the vacuoles, 

 and apparently always present, usually from 5 to 15 in each conidium ; 

 they are readily separated by slight pressure on the cover-glass. The 

 most usual form is that of roundish flat discs, less often conical and either 

 truncated or not, rarely cylindrical. The longest diameter varies be- 

 tween 2 and 8 //,, the thickness between 0*5 and 0*7 /a. They readily 

 swell up in hot water, lose their form, and retain only a stronger 

 refrangibility. The behaviour of these substances is given in detail, 

 from which the author draws the conclusion that they are of neither an 

 oily, resinous, nor albuminous nature. They differ also in their pro- 

 perties from all known carbohydrates, and most closely resemble Fremy's 

 fibrose. In germination they are used up in the formation of the germi- 

 nating tube, and must, therefore, from a physiological point of view, be 

 regarded as a reserve-substance. 



Secretion from the Roots.:}: — Dr. H. Molisch states that the acid 

 secretion from roots attacks organic even more powerfully than inorganic 

 substances, not merely dissolving them, but causing important chemical 

 changes. It exercises both a reducing and an oxidizing power. It 

 stains guaiacum blue. It oxidizes tannin and humin-substances, and 



* Bot. Ztg., xlv. (1887) pp. 849-57. 



t Ber. Deutsch. Bot. Gesell., v. (1887) pp. 275-81 (1 pi.). 



% SB. K. K. Zool.-Bot. Gesell. Wien, xxxvii. (1887) p. 65. 



