764 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Continuity of Protoplasm.* — G. Schaarsclimidt believes that all 

 vegetable cells inclosed in a cell-vpall and combined into a tissue 

 are placed in uninterrupted connection by means of threads of 

 protoplasm. 



With regard to the occurrence of protoplasm in intercellular 

 spaces, he finds intercellular masses of protoplasm in Liriodendron 

 tulipiferum, also in the bud-scales of ^sculus Hippocastanum, in 

 Solanum Pseudocapsicum, Viscuni album, &c. They occur especially 

 where the cells themselves contain no great quantity of protoplasm, 

 and can convert themselves into true cells by becoming invested with 

 a cell-wall ; secondary intercellular spaces are then formed between 

 these and the older cells. This intercellular protoplasm the author 

 believes to be derived from the threads which pass from cell to cell. 



Osmotic Power of Living Protoplasm.j — By an ingeniously 

 contrived apparatus M. Westermaier claims to have proved that the 

 pressure of the parenchymatous cells of the root-system, and the 

 osmotic suction of the protoplasm in the parenchyma of the stem, 

 acting together, are capable of raising a column of water to any given 

 height from the soil. 



Structure of Pollen-grains. J — J. Vesque points out that the 

 pores in the pollen-grains are so arranged that, no matter in what 

 position the grains fall on the stigma, one at least of the pores is 

 ordinarily in contact with the moist membrane of the stigmatic 

 papillae. The larger the grain the greater the number of pores (or 

 of folds), and their number, therefore, cannot be considered of great 

 taxonomic value. M. Vesque has found pollen-grains of Hieracium 

 having three to four pores, and that in the same anther. 



The disposition of the external ornamentation of the pollen-grain 

 does not appear to depend on its mode of development, but on a 

 fixed geometrical law — that of phyllotaxy. Thus the complex pollen- 

 grain of the Chicoracese, were it completely spherical, would be a 

 pentagonal dodecahedron; but as it is slightly ellipsoid, hexagonal 

 network is combined with the pentagonal. In the simplest case, that 

 which obtains in Scolymus, three hexagonal faces furnished with pores 

 are seen on the equator of the grain, the twelve remaining faces being 

 pentagonal. It is evident that the number of hexagonal faces in- 

 creases the more the grain approaches the cylindrical form. Thus 

 in Sonchus, Helminihia, and Laduca it has twenty-one faces, three 

 hexagonal ones with pores, six without, and twelve pentagonal ones. 



Seeds of Abrus praecatorius.i — W. Tichomiroff classifies the 

 seeds of Papilionaceae hitherto examined into three classes, according 

 to the nature of their reserve material, viz, : — (1) Seeds containing a 

 fatty oil, starch, glucose, and aleurone, such as AracJiis hypogcea and 

 Bipterix odorata ; (2) those containing starch and aleurone only, as 



* Magy. Nov. Lapok, viii. (1884) pp. 17-20. See Bot. Centralbl., xviu.(1884) 

 p. 162. 



t Ber. Deutsch. Bot. Gesell., i. (1883) pp. 371-83. 



% Comptes Eendus, xcvi. (1883) pp. 1684-6. 



§ SB. Vers. Euss. Naturf. u. Aerzte, Aug. 25, 1883. See Bot. Centralbl., 

 xviii. (1884) p. 189. 



