774 SUMMARY OF CURRENT RESEARCHES RELATING TO 



solution by saturation with sodium chloride, unless a large excess of 

 glacial acetic or phosphoric acid be added. 



The author concludes by saying that there are, therefore, two proteids 

 in the seeds of Ahrus precatorius, a vegetable paraglobulin and an 

 a-phytalbumose. 



Cholin in Seedlings.* — Herr E. Schulze records the presence of this 

 nitrogenous base in seedlings of lupin and gourd ; this was determined 

 by analysis of the double salt of gold and platinum. 



Crystalloids in Stylidium and iEschynanthus.t — Herr C, Eaunkiaer 

 finds crystalloids in the epidermal cells of the under-side of the corolla- 

 lobes of Stylidium adustum, and in the epidermal cells, especially of the 

 leaves, of several species of ^scJiynanihus. They occur in the form of 

 rhombic discs, 1-4 in each nucleus. They dissolve very rapidly on 

 addition of water or alcohol, but, as the author thinks, not from solubility 

 in the reagent, but from the access of the acid cell-sap. 



Occurrence and Function of Tannin in Tissues. J — Dr. M. Wester- 

 maier has investigated the conditions of the formation of tannin in a 

 number of both herbaceous and woody plants (Impatiens parviflora, Poterium 

 Sanguisorha, Alchemilla vulgaris, Mespilus germanica, Quercus pedunculata, 

 &c.). He considers its formation to be distinctly dependent on illumination; 

 in etiolated leaves and leaf-stalks it may even be altogether wanting. The 

 tannin increases in the assimilating cells in the light ; its increase and 

 decrease appear to depend to a large extent on the same conditions as the 

 increase and decrease of chlorophyll. 



True Nature of Starch Cellulose.§ — Herr Griessmayer has undertaken 

 an investigation to ascertain the true nature of the coating said to surround 

 the true grains of starch (granulose). Meyer considers this coating not to 

 consist of a compound present in the unaltered granule, but to be the result 

 of change of the starch. The coatings can be obtained by the following 

 method : 1000 grains of potato stai'ch are allowed to remain for 100 days 

 in 6 litres of 12 per cent, hydrochloric acid ; the coatings are then separated 

 and filtered off", and washed with water ; when dried they weigh about 300 

 grains, and when boiled in water they dissolve almost entirely ; there 

 remains, however, a small portion of cellulose tissue, fat, &c. ; from the 

 solution, cold causes the dissolved compound to separate, forming sphero- 

 crystals of amylodextrin. 



C4) Structure of Tissues. 



Differentiation of Epidermal Cells. |1 — Herr E. Heinricher observes 

 that in some plants belonging to the Cruciferaa some of the epidermal cells 

 are from 10 to 20 or even 100 times larger than the adjacent cells. These 

 large cells may be either solitary or associated in groups. This occurs in 

 the stem as well as the leaves ; in Halophila pilosa they attain a length of 

 8 mm. The object of these large cells appears to be to serve as a 

 storage of water ; they are found es2>ecially in species growing in very dry 

 situations; where they are present, even cut shoots remain a long time 

 without withering. 



* Zeitschr. f. Physiol. Chem., xi. p. 365. See Naturforsclier, xx. (1887) p. 261. 



t Bot. Tidsskr., xvi. (1887) pp. 41-5. See Bot. Oentralbl., xxx. (1887) p. 236. 



X SB. K. Preuss. Akad. Wiss. Berlin, ix. (1887) pp. 127-44 (1 pi.). 



§ Bied. Centr., 18S7, pp. 190-2. See Journ. Chem. Soc. Lond., 1887 — Abstr., p. 686. 

 Cf. this Journal, cmte, p. 256. 



II MT. Naturw. Ver. Steiermark, 1886, 29 pp. and 1 pi. See Bot. Centralbl., xxx. 

 (1887) p. 305. 



