764 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Pericarp of Compositse.* * * § — Herr 0 . Heineck describes in detail the 
minute structure of the pericarp of Compositse, and classifies the various 
forms under eight types, dependent on the arrangement of the “ hard- 
bast-cells ” which he finds always present in the pericarp, — elongated 
fusiform cells with a small cavity, and distinguished by these characters 
from the soft-bast-cells or cells of the bast-parenchyme. 
Structure of Seed of Euonymus.j - — From an examination of the 
structure of the seed of Euonymus japonicus , Sig. E. Baroni confirms 
the view taken by Planchon and Gasparrini, that the so-called arillode is 
not a true aril, inasmuch as it does not proceed from the micropyle, but, 
in its outer layer, is in complete continuity with the podosperm and 
with the raphe. The red pigment of this mantle is probably derived 
from the chloroplasts already existing in the unripe seed. 
Structure of Cotyledons.]: — Herr F. Simek describes the structure 
of the cotyledons in species belonging to the Caryophyllacese, Gerani- 
acese, and Compositse. In the Caryophyllacese, where the cotyledons 
differ considerably in form and size from the foliage-leaves, the first 
two pairs of the latter always form a connecting link between the 
cotyledons and the normal leaves, and may be termed “ primordial 
leaves.” Generic, and in some cases specific, characters may at times 
be obtained from the cotyledons. In the Geraniacess the cotyledons 
always differ considerably in form from the normal leaves, but there are 
no primordial leaves or other connecting links. Among Compositae, 
in Tragopogon the cotyledons have also, like the foliage-leaves, a long 
narrow form with entire margin. 
Stem of the Cymodocese.§ — M. C. Sauvageau, having already de- 
scribed the specific differences of structure observable in the leaves of 
Cymodocea and Halodule , now points out that the Cymodocese of the 
section Phycagrostis, and particularly C. serrulata, are better characterized 
by the structure of the stem than by that of the leaf ; on the contrary, 
however, for the determination of the species of Phycoschsenus and 
Halodule , it is preferable to have the leaf. The nine species of 
Cymodocese are taken seriatim, and the structure of the stem carefully 
described in each. The structure, although comparatively simple, and 
showing some analogies with Zostera , presents certain variations between 
one species and another. For instance, in C. serrulata the cortical 
parenchyme is the same as that met with in C. sequorea, while the form 
and structure of the central cylinder is that of the Cymodocese of the 
section Phycoschoenus ; finally the lignified cortical fibrous bands are not 
met with in any other species. 
Swellings in the Bark of the Copper-beech. || — Herr F. Krick has 
examined the structure of the so-called tubers which frequently occur in 
the bark of the copper-beech, and which consist of true woody tissue, 
* ‘ Beitr. z. Kenntniss.d. feineren Baues d. Fruclitschale d. Oompositen,’ Giessen, 
1890. See But. Centralbl., 1891, Beih., p. 112. 
f Nuov. Giorn. Bot. Ital., xxiii. (1891) pp. 513-21. 
j JB. Deutsch. Staats-gymn. Prag, 1889. See Bot. Centralbl., 1891, Beih., 
p. 203. 
§ Journ. de Bot. (Morot), v. (1891) pp. 205-11, 235-43 (6 figs.). Cf. this Journal, 
ante , p. 65. 
|| Biblioth. Bot. (Luerssen u. Ilaenlein), Heft 25, 1891 (28 pp. and 2 pis.). 
