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CURRENT LITERATURE. 
BOOK REVIEWS. 
Latex and mucilage. 
TO THE already extensive literature of the laticiferou; tissues, Molisch 
contributes an important addition,* differing from its predecessors in giving 
chief attention to the constitution, both organic and chemical, of the latex 
itself. In his investigations he used living material and fresh latex, as well 
as that which had been fixed and stained. Molisch has confirmed and 
extended the earlier observations of Treub, Johow, and Schmidt on the exist- 
ence of a plasmic membrane and nuclei in the latex tubes, for demonstrating 
which he recommends Euphorbia splendens and Poinsettia pucherrima. He 
finds the membrane lining the latex vessel and constituting an inner living 
tube within which the latex is formed like the cell sap. Special examination 
of the nuclei shows that some nuclei are very different from those of ordinary 
plant cells, having characters not before known in nuclei of any plant or 
animal. Molisch calls them Blasenkerne. The granular nucleus seems to 
lie centrally or excentrically in a relatively large globular vacuole, but really 
the vacuole is in the nucleus, the nuclear sap filling the space between the 
nuclear material and the membrane. Nuclei of somewhat irregular form are 
also present. Various phenomena lead to the conclusion that the nuclear 
membrane is an independent, clearly differentiated organ. 
Besides the nuclei there are imbedded in the plasma leucoplasts of dif- 
ferent kinds. Some form the elongated starch grains; others (proteino- 
Plasts”) produce proteid granules, a phenomenon which has recently been 
observed also by Heinricher in Lathraea. Crystals of proteids or proteid-like 
substances are also produced, not anywhere in the contents of the latex tubes, 
but by the agency of special plastids or of vacuoles. Molisch also finds 
elaioplasts and vacuoles responsible for the formation of oil drops. 
Into the details of the chemistry of the latex we cannot follow the author. 
The latex he finds usually acid, rarely neutral, and never alkaline; calcium 
Salts and chlorids are variable in amount ; magnesium compounds are abun- 
dant and sometimes accumulate in extraordinary quantity; proteids and 
Carbohydrates are so abundant that one must look upon the latex tubes as 
Special reservoirs of these foods. : 
As the latex is an emulsion, the fine division and 1 ly great 
*MoLiscu, Hans: Studien iiber den Milchsaft und Schleimsaft der Pflanzen. 
8vo, pp. viii 111, figs. 33. Jena: Gustav Fischer. 1901. M4. 
Igor] 369 
