234 



XOTES ON 8ECTIONINC4 WOODY TISSUES. By JOHN S. WeIGHT. 



[Abstract.] 

 The preparation of hard, woody tissues for sectioning is accomplished by 

 heating the pieces to be sectioned a few minutes in a test tube containing 

 a 75 per cent, or 50° glycerine solution. The woods may thus be quickly 

 brought into condition for sectioning. In some instances the glycerine 

 and heat distort the tissues, while in other cases, if carefully applied, they 

 may restore cells, which have shrunken, to nearly their original outline. 

 By this method, however, all starch grains of the cells are destroyed, and 

 when it is desired to studv cell contents fresh material must be secured. 



Concerning the effect of glycerine on plants. By John S. Wright. 



[ABSTRAtl'.j 



Various potted plants were experimented with, particularly geraniums. 

 Glycerine was administered to them in the water. 10, 20, 25 per cent, 

 solutions were used. In some cases wilting was soon effected by the appli- 

 cation of water containing glycerine. Some cases showed a temporary 

 revival from the first noticed effects, again in other cases the plants died. 

 Chemical tests were made of leaves of treated plants and of untreated 

 ones (those of control experiments) and in nearly all instances treated 

 plants were discovered to have contained glycerine in their tissues. 



Contributions to the histology of the pontederiace.e. By E. W. Olive. 

 [Abstract.] 



Pontederia cra»dpes, a cultivated form, is taken as a representative of 

 the order and its histological structure compared with the other species. 

 It, however, is not typical, because of its higher differentiation. The dia- 

 phragm, of stellate tissue of these aquatic monocots furnish very inter- 

 esting studies. These probably serve other more important functions 

 than that of mere mechanical support. The active nuclei indicate a close 

 connection with the vital processes of the plant. 



The diaphragms in Pontederia cordata and P. crassipes are pierced by 

 long spear-like crystals of calcium oxalate. Each of the latter are en- 

 closed in a thick- walled sac. Also a secretion of a fatty-oil nature was 

 abundant in all the partitions except those of Pontederia crasdpes. Con- 

 centrated sulphuric acid placed on a section showed a beautiful example 

 of continuity of protoplasm in the cells of the diaphragm. 



