ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
191 
My rosin.* — M. L. Guignard describes the mode of extraction of this 
substance from the plants in which it is found, and its behaviour with 
various reagents. The property which specially distinguishes it from 
other diastases is that of decomposing potassium myronate. In the 
leaves of Carica Papaya and Sinapis nigra , myrosin is accompanied by 
two other ferments, neither of which possesses this power. One of them 
has the properties of invertin, the other those of the diastase of germina- 
ting barley. 
Poisonous Principle of the Cactacese.f — In Anlialonium Lewinii 
and some other species of Cactaceae, Herr L. Lewin finds a poisonous 
alkaloid to which he gives the name anlialonine ; its properties resemble 
those of strychnine. 
Phosphorus in Vegetable Tissues.;}; — Dr. G. Pollacci has established 
the general presence of phosphorus in vegetable tissue, and its necessity 
for certain vital processes. It was found to be absent from the cell-wall, 
but present in appreciable quantities in the protojdasm, and especially 
in the chromatin grains of the nucleus. It occurs also in the hyphse and 
spores of Fungi. In the vegetative organs of the higher plants it is 
found to be accumulated especially in the meristem and in the conduct- 
ing tissues. The parts of the flower most rich in phosphorus are the 
ovules and the pollen-grains ; the nucleus of reproductive cells contains 
a much larger quantity than that of vegetative. In the seeds it is stored 
up especially in the embryo. 
(3) Structure of Tissues. 
Formation of Lysigenous Cavities.§ — Dr. F. C. Newcombe has 
studied this subject in a large number of plants, and gives the following 
as his more important conclusions. Whether the cavity shall appear 
during or subsequent to primary growth depends on the cessation or 
retardation of extension in the tissue where the cavity appears, relatively 
to the extension of the more peripheral tissues. The mode of formation 
in primary growth is always at first schizogenous, and may also be 
schizogenous in secondary growth by the contraction of cells through 
the loss of turgor. But a lysigenous mode of formation always comes 
into play during primary growth. During secondary growth, the 
schizogenous factor, if present, is always small. In some species of 
plants the cavities in the pith are formed sometimes during primary, 
sometimes during secondary growth. The formation of a lysigenous 
cavity during primary growth may be somewhat deferred by preventing 
the normal primary extension of peripheral tissues ; and generally, the 
formation of cavities during both primary and secondary growth may be 
greatly deferred by preventing the extension of the surrounding 
tissues. 
Displacement of Bast-fibres. || — Prof. S. Schwendener has investi- 
gated the cases of alleged displacement of bast-fibres, attributed by 
* Bull. Soc. Bot. France, xli. (1894) pp. 418-28. Cf. this Journal, 1894, p. 468. 
t Ber. Deutsch. Bot. Gesell., xii. (1894) pp. 283-90. 
£ Malpighia, viii. (1894) pp. 361-79. Cf. this Journal, 1894, p. 476. 
§ Ann. Bot., viii. (1894) pp. 403-21. 
j| Ber. Deutsch. Bot. Gesell., xii. (1894) pp. 239-48 (2 figs.). Cf. this Journal 
1 885, p. 89. 
