346 SUMMARY OF CURRENT RESEARCHES RELATING TO 
examined), the former among Dicotyledons (8 out of 12 species). From 
this the author concludes that the Monocotyledons are the older type. 
The chromatophore system exhibits a gradual advance in complexity in 
ascending from the lower to the higher types of vegetable life, attains 
its highest degree of development in the Monocotyledons, and then again 
declines in the Dicotyledons. In the true Algae there are no leucoplasts. 
In the Chlorophyceae there are chloroplasts, in the Phaeophyceae phaeo- 
plasts, in the Phodophyceae ( Florid eae) rhodoplasts. In the Characeae 
there are both chromoplasts and leucoplasts. The Muscineae contain 
leucoplasts, but their function is of small importance. In the Vascular 
Cryptogams and Gymnosperms the structure attains a higher development, 
though not equal to that of the Angiosperms. In many Dicotyledons 
the leucoplasts have again entirely disappeared. The first formation of 
a grain of starch is probably due to a deposit of amylodextrin. The 
property of polymerizing carbo-hydrates of a low molecular weight 
probably resided at first in the leucoplasts, although in many of the 
higher plants it has passed to the protoplasm. 
Morphology and Formation of Starch-grains.* — Herr A. Binz has 
followed out the mode of formation and the structure of starch-grains, 
especially in Pellionia Daveauana. The grains are composed of an 
enormous number of layers, some more and some less dense, of which 
the latter are by far the most numerous. The author states that his 
observations contradict Nageli’s theory that the layers are formed by the 
splitting of layers previously in existence. The outer layers are always 
the youngest, and the inner ones the oldest. These facts strongly cor- 
roborate the theory of apposition. The chloroplast consists of a homo- 
geneous matrix or stroma, with imbedded pigment-granules or grana. 
The starch-generators are present in the growing points as leucoplasts ; 
they are structures homologous to the chloroplasts, into which they are 
directly transformed under the influence of light. They multiply by 
simple division. Compound starch-grains are formed in two ways — 
either several grains are formed in a single starch-generator (epiderm 
of Philodendron , Pellionia , Symphytum tuberosum, Convallaria, Odonto- 
glossum, Epipactis palustris), or several starch-generators unite into groups 
(pith of Philodendron , Convallaria , Stanhopea ). 
Localization of the Fatty Oils in the Germination of Seeds.f — 
M. E. Mesnard states that in a large number of cases examined by him 
(excluding grasses), the fatty oils are not localized in the germination 
of the seeds ; they behave like the albuminoids which they ordinarily 
accompany. In grasses (wheat, rye, barley, maize), during the period 
of repose, these oils are found" only in the scutellum and in the embryo ; 
subsequently starch makes its appearance in the scutellum, and, together 
with the oils and the albuminoids, passes into the growing embryo. 
Iron-greening Tannins. :[ — Mr. S. Le M. Moore, by the use of 
Millon’s reagent, obtains further confirmation of his view that the 
substance in certain cell-walls which causes them to give several of the 
* Flora, lxxvi. (1892) Erganzungsband, pp. 34-91 (3 pis.). Cf. this Journal, 
. 1892, p. 497. 
t Comptes Rcndus, cxvi. (1893) pp. 111-4. 
t Journ. of Bot., xxxi. (1893) pp. 52-3. Cf. this Journal, 1892, p. 630. 
