612 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Proteolytic Enzyme of Nepenthes. — Herr A. Hansen* * * § calls atten- 
tion to the fact that Czapek, in his notice of Vines’s work on the proteo- 
lytic enzyme of Nepenthes , has ignored his own work on the subject 
(1885). He states that the products of digestion obtained by Vines and 
others are not pure substances. 
To this F. Czapek f replies, and maintains that the results obtained 
by Vines are an advance on those previously recorded by Hansen. 
Encapsuling of Starch-grains. + — Dr. L. Buscalioni gives another 
example of this phenomenon, in the cortex of the root of Juncus tenuis. 
After giving in detail the result of microchemical investigations, he 
states that, as in the case of the seeds of Vida narhonensis , under the 
influence of special factors not yet well determined, there may be formed, 
around starch-grains, a membrane of a mucilaginous character, possibly 
of a pectic-cellulose composition, analogous to that found by Rosanoff 
surrounding crystals of calcium oxalate. 
Craterostigma pumilum.§ — Prof. H. M. Ward and Miss E. Dale 
describe this rare plant from Somali-land, belonging to the Scrophu- 
lariaceae. Its most remarkable characteristic is a red colouring matter 
of the roots, contained not in the cells, but in the intercellular spaces. 
The pigment appears to be present in the form of rounded non-crystalline 
granules, which may possibly be resinous, and which, in their micro- 
chemical reactions, most closely resemble the colouring matter in the 
flowers of Aloe. The authors regard it as a product of excretion. 
Cane-sugar in Plants.|| — According to Herr E. Schulze, cane-sugar 
is widely distributed in the ripe seeds of plants, although often present 
only in small quantities. It occurs in the seeds of conifers. It is pro- 
bably of importance as a reserve-material to be used in germination ; 
but, since it increases as growth goes on, it must fulfil other uses as 
well. Accompanying the cane-sugar, other soluble sugars capable of 
inversion are also present, sometimes in large quantities. 
Copper in Plants.1T — 1 To the instances recorded of the occurrence of 
copper in a number of different plants, M. E. Heckel now adds Quassia 
gabonensis, where he finds an appreciable amount in the seeds. 
(3) Structure of Tissues. 
P Growth of the Thickening-Ring in Dicotyledons. **— -Rosseler, 
Mischke, and Eaatz have already shown the incorrectness, with regard 
to Monocotyledons and Gymnosperms, of Sanio’s “ initial-theory,” that, 
in a radial row of cambium-cells, only a single one, the “ initial cell,” 
gives off cells on the outside and the inside, while their daughter-cells, 
before their development into xylem- and phloem-elements, can divide 
at most only once. Herr M. Nordbausen now extends his observation 
* Bot. Ztg., lvii. (1899) 2 te Abt., pp. 267-9. Cf. this Journal, ante, p. 292. 
f Tom. cit., p. 269. 
t Malpighia, xiii. (1899) pp. 3-13 (1 pi.). Cf. this Journal, 1898, p. 207. 
§ Trans. Linn. Soc. (Bot.), v. (1899) pp. 343-55 (2 pis.). 
|| Zeit. phys. Chem., xxvii. (1899) pp. 267-91. See Journ. Chem. Soc., 1899, 
Abstr. ii. p. 570. 
If Bull. Soc. Bot. France, xlvi. (1899) pp. 42-3. Cf. this Journal, ante, p. 292. 
** Beitr. z. wissensch. Bot. (Fiinfstuck), ii. (1898). See Bot. Centralbl., lxxix. 
(1899) p. 62. 
