466 SUMMARY OF CURRENT RESEARCHES RELATING TO 



BOTANY. 



A. G-ENERAli, including the Anatomy and Physiology 

 of the Phanerogamia. 



a. Anatomy.* 



Continuity of Protoplasm.! — Mr. S. Le M. Moore has studied the 

 phenomena connected with the continuity of protoplasm in several 

 species of Strychnos, and describes the difference presented in the . 

 different cases, as also in Diospyros emhryopteris and melanoxylon. As 

 a staining material he finds Judson's Oxford-blue and Sands' blue to 

 answer as well as Hofmann's blue recommended by Gardiner. For 

 permanent preparation the best mounting medium is water or calcium 

 chloride. Mr. Moore dissents from Tangl's statement that the 

 employment of ordinary reagents causes in all cases total plasmolysis. 

 The best way of observing plasmolytic threads is to place sections in a 

 drop of solution of iodine in alcohol on a slide, a minute or so after- 

 wards placing a cover-slip upon them, and examining either in this 

 state, or after addition of a small quantity of water. Although easily 

 overlooked, the threads can then readily be made out with care ; in 

 many cases they may be seen to run into the intramural threads. 



The author then proceeds to describe the phenomena of continuity 

 in a considerable number of Floridese. He adopts the view that the 

 continuity is always direct in the early history of the cells, and in some 

 cases {Chondrus, Polyides, Furcellaria) persistently so ; while in others 

 direct continuity may persist in one part of the thallus, and be 

 supplanted by the indirect form in another (Ceramium ruhrum, &c.). 

 The young cells are placed in communication by means of a fine 

 filament, upon which is in most cases placed a small nodule, just as a 

 bead is strung upon a thread. The ground for this statement is that 

 in surface-views of the nodule only a single small central pore can be 

 seen, and that the thread itself, as slender as the single threads piercing 

 the membrane of rings, cannot be seen to undergo division in passing 

 the nodule. Attention is called to the rapid growth of the thread, 

 accompanied by concurrent growth of the nodule to form a ring. 



Currents of Protoplasm. J — Herr A. Wigand distinguishes seven 

 kinds of protoplasmic currents in the vegetable cell, viz. — (1) Circu- 

 lation, when the currents cross one another in different directions in 

 the cell-cavity, and unite in rays round the nucleus which is suspended 

 in the cavity. (2) Eotation, when the protoplasm moves in simple or 

 branched paths, and the nucleus is applied to the cell-well. (3) The 

 currents observed in the young endosperm-cells of Ceratophyllum, 



* This subdivision contains (1) Cell-structure and Protoplasm (including the 

 Nucleus and Cell-division ; (2) Other Cell-contents (including the Cell-sap and 

 Chlorophyll) ; (3) Secretions ; (4) Structure of Tissues ; and (5) Structure of 

 Organs. 



t Journ. Linn. Soc Lond. (Bot.), xxi. (1886) pp. 595-620 (3 pis.). 



i Forsch. a. d. Bot. Garten Marburg, i. (1885) pp. 169-224. See Bot. 

 Centralbl., xxv. (1886) p. 4. 



