ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 427 



BOTANY. 



A. GENERAL, including the Anatomy and Physiology 

 of the Phanerogamia. 



a. Anatomy. 

 (2) Cell-Contents (including- Secretions}. 



Formation of Anthocyan.* — Dr. L. Linsbauer calls attention to the 

 fact that mechanical injury causes in many plants the production in the 

 cell-sap of a red pigment identical with the anthocyan of flowers. It is 

 most common in woody plants, and usually begins to be formed in the 

 palisade-tissue. The author attributes the phenomenon to a decrease, 

 resulting from the injury, in the power of the tissue in question to 

 transport certain special cell-contents, or to the destruction of a har- 

 monious relationship between assimilation and conduction. 



Latex and Mucilage-Sap. f — Prof. H. Molisch gives an exhaustive 

 treatise on this subject. Laticiferous tubes are multinucleated living 

 cells, the membrane being lined with a layer of protoplasm which con- 

 tains nuclei, leucoplasts, vacuoles, and other bodies ; the nuclei differ 

 greatly in size and form in different plants ; they are especially dis- 

 tinguished by their distinct membrane. Under leucoplasts the author 

 includes not only those bodies which form starch, but also those which 

 excrete oil or albumen. Starch was observed only in the laticiferous 

 tubes of the Euphorbiacere, Nerium Oleander, and Allamanda Schottii. 

 Proteinoplasts containing protein-grains occur abundantly in the latex 

 of Cecropia peltata and other plants. Related to them are the remark- 

 able albuminoid bodies of Aroideae, the albuminoid-crystalloids of the 

 Apocynaceae, and the crystalloids in the vacuoles of Jatropha, Masa, &c. 



The latex is usually acid, very rarely neutral, and never alkaline ; 

 hence it must be regarded as a cell-sap rather than as a form of proto- 

 plasm. It sometimes contains great quantities of lime (Euphorbia 

 Lathyris) or magnesia (Ficus elastica). In some cases (Garica Papaya) 

 it contains a ferment. The latex of the Musaceae and Aroideae is rich 

 in tannin. 



Mucilage -sap (Scldeimsaft) is not nearly so widely distributed as 

 latex, at all events in special tubes. It is described in the case of the 

 Liliaceas, Amaryllideae, and Commelynaceae. The mucilage-tubes re- 

 sult from the coalescence of cells ; each chamber contains one or more 

 nuclei, and often a bundle of raphids. The contents have usually an 

 acid reaction. A new substance, luteotilin, is described occurring as 

 sphaero-crystalls in the mucilage of many Amaryllideaa, Liliaceae, 

 Commelynaceae, Gramineae, and Lobeliaceae. 



* Oesterr. Bot. Zeitschr., li. (1901) pp. 1-10. 



t ' Studien iib. d. Milchsaft u. Schleimsaft d. Piianzen,' Jena, 1001, 111 pp. and 

 33 figs. See Bot. Centralbl., Ixxxvi. (1901) p. J 7. 



