214 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
cell, sometimes finally reaching the cell -wall. Another anomalous process- 
is termed by the author gemmation. The nucleus puts forth emergences,, 
which subsequently become detached. This was observed especially with 
nuclei of very large size, and sometimes all stages of the process were 
met with in the same cell. It is probably a process of degeneration. 
(2) Other Cell-Contents (including Secretions}. 1 
Pigments of Plants.* * * § — Miss M. J. Newbigin gives a detailed account 
of the various colouring matters of plants, dividing them into lipo- 
chromes, which are insoluble, and anthocyans, which are soluble in 
water. There is no evidence that lipochromes are in any way deriva- 
tives of chlorophyll. The authoress groups them in two classes — 
eucarotins and carotinins. Anthocyans are probably derivatives of 
tannins. The usual theory, that their purpose is to prevent the decom- 
position of chlorophyll in . a strong light, is scarcely in harmony with 
some of the conditions under which they are commonly formed, as, for 
instance, in young shoots in spring and in autumn leaves. Etiolin is 
probably nearly allied to chlorophyll, which it resembles in containing 
nitrogen, while most other plant-pigments are non-nitrogenous. 
Formation of Gum by Aralia spinosa.f — M. L. Lutz finds the seat 
of formation of gum in this species to be almost exclusively the phloem 
of the vascular bundles ; the cortex, pericyclo, xylem, and pith are almost 
unaffected by it. It is formed alike in the root, the stem, and the leaves. 
The process goes through two stages ; the first is very rapid, resembling 
the formation of mucilages ; the second is much slower, partaking more 
of the character of the production of a true gum. „ 
Colouring-Matter of the Tomato.J — Herr C. Ehring finds the pig- 
ment of the tomato to be a cholesterin closely allied to the carotin of 
the petals of Calendula. 
(4) Structure of Organs. 
Young Form of Plants.§ — Prof. K. Goebel adduces a variety of 
instances, chiefly belonging to the Muscinem and Pteridophyta, in which 
the young form — protoneme, prothallium — is more or less retained in 
later life, or in which it can be again called into existence, especially by 
placing the plant in unfavourable vital conditions. This is especially 
well seen in Funaria hycjrometrica. If the rudimentary buds are culti- 
vated in the dark, they revert to a protoneme condition, even after the 
wedge-shaped apical cell has already been formed, the cells growing out 
into filaments. In Schizostega osmundacea a similar process takes place 
in nature, shoots of limited growth being formed, the rudimentary leaves 
of which, together with their apical cell, are of only temporary duration. 
In Ferns, shutting off the light will cause the prothallium to revert to 
* Trans. Bot. Soc. Edinburgh, xx. (1896) pp. 534-50. 
t Bull. Soc. Bot. France, xliii. (1896) pp. 513-6 ; Journ. de Bot. (Morot), xi. 
(1897) pp. 91-5 (2 figs.). Cf. this Journal, 1896, p. 81. 
+ ‘Ueb. d. Farbstoff d. Tomate,’ Munster, 1896, 35 pp. See Bot. Centralbl.,lxix. 
(1897) p. 154. 
§ SB. Iv. Bayer. Akad. Wiss. Munchen, 1896 (97), pp. 447-97 (16 figs.). Cf. this- 
Journal, 1889, p. 550. 
