314 BOTANY. 



VEGETABLE ANATOMY AND PHYSIC LOGY. 



An importaut paper by Pringsheim on tlie Action of Light and the 

 Function of Chlorophyl was communicated to the Berlin Academy in 

 July of this year. The paper is in the nature of a somewhat lengthy 

 preliminary communication which the writer intends to give in full with 

 illustrations in his Jahrbiicher. Pringsheim reports the discovery of a 

 substance, to which he gives the name of HypocUorin or Rypochromyl, 

 which is obtained from chlorophyl-bearing tissues by allowing them to 

 remain in dilute hydrochloric acid for several hours. The Hypochlorin 

 then appears in the form of small, viscid drops or masses of semi-fuid 

 consistency, which ultimately are transformed into long, reddish-brown, 

 indistinctly crystalline needles. According to Pringsheim, he has proved 

 that chlorophyl, by its power of regulating plant-respiraiion in light by 

 means of its absorption of the most active chemical rays, depresses the 

 amount of respiration in green plants exposed to the light below the 

 amount of assimilation, and so makes possible the accumulation of car- 

 bon-products and the persistence of the plant in the light. Hoppe-Seyler 

 has discovered a substance to which he gives the name of Chlorophyllan, 

 which has the form of dark green, velvety-looking plates, which are 

 curved and often united in rosettes. Gautier, in the Comptes Rendus, 

 regards the chlorophyllan of Hoppe-Seyler as crystallized chlorophyl 

 itself, and he claims for himself the priority of its discovery. The Helio- 

 troiric Fhenomena of Plants is the title of a monograph by Wiesner, first 

 presented to the Vienna Academy in 1878, but not generally made public 

 until the present year. 



The Annales des Sciences contain an article by Bonnier on nectaries, 

 and a copiously illustrated paper by Yesque, Sur le Sac Uitibryonnaire, 

 in which he supports the views of Warming as to the signification of the 

 embryo-sac, rather than the views of Strasburger. L. Koch, in his mono- 

 graph of the Development of the Crassulacew, gives a large number of 

 finely drawn plates of the microscopic structure of species of that order. 

 The mode of fertilization in Zostera marina has been studied by Engler, 

 who criticises unfavorably the views on the subject formerly held by 

 Hofmeister. 



The American ]S"aturalist contains a number of short papers on fertil- 

 ization, amoug which may be mentioned: Certain Contrivances for Cross- 

 fertilization in Floivers, by Prof. J. E. Todd ; On tlie Fertilization of several 

 species of Lohclia^ by William Trelease ; The Fertilization of our native 

 species of Clitoria and Centrosema, also by Trelease j and On the Fertili- 

 zation of Yucca, by Thomas Meehan, a paper read before the Am. Ass. 

 for the Advanc. Science. In the Botanical Gazette are papers on Tri- 

 morphism in Lithospermum canescens, by E. F. Smith, and on Sexual differ- 

 entiation in Fpiga'a repens, by L. F. Ward, and a note on the movement 

 of the stamens of Sahbatia angularis, by the same author. In the Am. 

 Journ. Science Prof. W. J. Beal describes his Experiments in Cross-breed- 



