ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
57 
germinating seeds of Lupinus and Cucumis there are a larger or smaller 
number of globular stainable particles which may be regarded as 
secondary nucleoles. 
Tonoplasts.* — Dr. C. Acqua reviews the recent literature on this 
subject. While admitting the value of De Vries’s discovery of the 
special functions belonging to the membrane of vacuoles, he considers 
that its importance has been exaggerated by its discoverer, and especially 
by Went. He disputes the statement that vacuoles can only be formed 
by the division of others previously in existence, the evidence in favour 
of which he considers to be very slight. He lays great stress on the 
evidence in the opposite direction furnished by the observation of Klebs 
that in Hydrodictyon reticulatum the original vacuole remains unchanged 
during the formation of the very numerous zoospores. 
(2) Other Cell-contents (including- Secretions). 
Formation of Starch-grains and Chlorophyll-bodies.f — M. E. 
Belzung reiterates his arguments against Schimper’s view that the for- 
mation of starch-grains is due to special structures which he calls 
leucites. In the plants observed by him (Leguminosse) the protoplasm 
of the undeveloped embryo presents itself in the form of a network which 
at no time incloses bodies comparable to those termed leucites ; the 
grains of starch come into existence at the free parts of the cell, i. e. in 
the meshes of the protoplasmic network, precisely like crystals or other 
similar formations. The meshes of the network contain the cell-sap and 
inclose the nucleus. The starch-grains are at this period simple. When 
the embryo is mature, the protoplasmic network has passed into the 
condition of a granular secondary network, and the starch-grains have 
united into compound grains. In opposition, therefore, to the generally 
accepted view that starch-grains are always formed within chlorophyll- 
bodies, and as a result of the activity of the latter, the author maintains 
that the starch-grains are first formed, and are the source of the chloro- 
phyll-bodies. 
Distribution of Aleurone-grains.f — Herr F.Ludtke has investigated 
the form, size, and distribution of the aleurone-grains in the seeds of a 
number of different plants. He confines the term to those bodies which 
always contain one or more globoids, and may contain crystalloids or 
crystals. 
The solubility of the ground-substance of the grains in water was 
found to vary in different species. Seeds which contain a large amount 
of oil, or which also contain cellulose or starch as reserve food-materials, 
have only a small number of aleurone-grains, at most only three or four 
in a cell, and these usually adpressedto the wall. But in most seeds the 
cells are densely filled with aleurone-grains, which become polyhedral in 
form through mutual pressure. The distribution of the grains also differs 
in different parts of the same seed. 
The author considers the size of the aleurone-grains to be of con- 
siderable value in the diagnosis of substances used in pharmacy. 
* Mitlpighia, v. (1891) pp. 106-15. Cf. this Journal, 1888, p. 981. 
+ Ann. Sci. Nat. (Bot.), xiii. (1891) pp. 5-22 (1 pi ). Cf. this Journal, 1891 
p 362. 
t Ber. Pharrn. Gescll., 1891, pp. 53-9. Sec Bot. Centralbl., xlviii. (1891) p. 50. 
