66 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
are some traces of oil-deposits, but it is of the same not clearly 
developed tyjie. Upland Georgia cotton is beautifully developed, clean 
in outline, well formed, full of oil-dej:)osits, and with very good spirality. 
The finest cotton raised anywhere in the wmidd is the Mississippi 
delta cotton ; beautiful in its structure, perfect in its developments, 
full of oil-deposits, and with a spirality of nearly 400 per inch. 
Wiesner’s Biology of Plants.* — This work treats in detail of vege- 
table biology, arranged under the four following heads:— (1) Life of 
the individual ; (2) Biology of reproduction ; (3) Development of the 
vegetable kingdom; (4) Distribution of plants. Under the first head 
is given a review of jdant-forms according to their mode of life, and a 
chapter on the origin and development of organs. 
B. CRYPTOGAMIA. 
Cryptogamia Vascularia. 
Meristem of Ferns.f — Prof. U. O. Bower has made an extended 
comparative examination of the meristem of a great variety of ferns, as a 
phylogenetic study. The following are the general conclusions arrived 
at, which tend to accentuate the contrast between the eusporangiate and 
the leptosporangiate series of Filicineae. 
As regards the roots, the apices of those of the leptosporangiate 
ferns are comparatively small, while those of the Osmundaceae are larger, 
and those of the Marattiacem still larger. In the leptosporangiate ferns 
the apex of the root has always one tetrahedral initial cell ; but in the 
Osmundaceae there are often three or four initial cells. The initial 
cells of the Osmundaceae and Marattiaceae are narrower and deeper in 
proportion than in the leptosporangiate ferns, and are often not pointed, 
but rectangular at the base. In respect of the structure of the apex of 
the root, the leptosporangiate ferns, Osmundaceae and Marattiaceae, con- 
stitute an ascending series. 
In the stem the apex of most leptosporangiate ferns is distinctly 
conical, while in Osmundaceae and Marattiaceae it is flatter and larger. 
In other respects the conclusions drawn from the comparative study of 
the apices of the stem in the three classes closely correspond to those 
drawn from the roots. 
A comparative study of the apices of the leaves leads to the same 
general results. In the leptosporangiate ferns a two-sided apical cell 
with regular segments is the type for the leaf, though with a few 
irregularities ; while in Osmundaceae a three-sided apical cell with 
three rows of segments is the rule ; and in Angiopteris (Marattiaceae) the 
apex is occupied, not by one initial cell, but by a number, apparently 
three. The leptosporangiate ferns, Osmundaceae and Marattiaceae, there- 
fore again form a series gradually increasing in complexity. 
In the large majority of ferns the leaves are winged, and these 
wings may be traced, more or less distinctly, from the a^eex to the base 
of the leaf. In the Hymenophyllaceae they are delicate and thin ; in the 
* ‘ Biologie der Pflauzen,’ Wien, 1889. See Bot. Centralbl., xxxix. (1889) p. 286. 
t Ann. of Bot., iii. (1889) pp. 305-92 (5 pis.). 
