ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
739 
possesses an additional bundle-system in tlie pith. With regard to the 
leaves, it is seldom that any anatomical character can be assigned to 
a particular species, the histological characters of the leaf varying greatly 
in the same species under the influence of climate and of habitat. The 
arrangement and distribution of the stomates is very uniform, but they 
may either be elevated above the surface of the epiderm or depressed 
beneath it, according as the individual grows in a moist or in a dry 
situation. 
Anatomy of Keteleeria.* — Sig. R. Pirotta has examined the 
anatomical structure of Keteleeria Fortunei , a monotypic conifer; the 
following being the most important results obtained. The root is 
characterized by the presence of a primary resiniferous axial canal, and 
of secondary resin-canals arranged irregularly in the secondary wood, 
and by the presence of mucilage-bearing idioblasts in the secondary 
cortex. The branches also contain resin-canals and mucilage-bearing 
idioblasts in the primary cortex, while these are absent from the 
secondary cortex and secondary wood. The leaves are of bilateral 
structure with heterogeneous mesophyll, and contain two lateral and 
marginal resin-canals and mucilage-bearing idioblasts in the mesophyll. 
On the under surface of the leaf the stomates form two broad zones on 
the sides of the mid-rib ; there are none on the upper surface of the leaf. 
(4) Structure of Organs. 
Andrcecium of Malvacese.t — From an examination of the develop- 
ment and structure of a number of plants belonging to the natural order 
Malvaceae, and especially to the tribe Malveae, Herr J. W. C. Goethart 
derives the following general conclusions. The androecium owes its 
origin to the activity of intercalary meristem in close connection with 
the petals, and developed more strongly on their anodic side. These 
form the “ staminalpodes,” which produce the rows of stamens on their 
margins in basipetal succession. The rudiments of stamens, which 
originally stand in two vertical rows, usually split tangentially, each into 
two stamens with two-lobed anthers, sometimes into four. Variations 
occur in the number of the stamens, in the displacement of the staminal- 
podes, and in other points. The displacement of the staminalpodes is 
apparently caused by the oblique insertion of the petals. The diminu- 
tion in the number of stamens in the androecium appears to be due either 
to climatic influences or to reversion. 
Development of the Seminal Integuments of Angiosperms.J — 
M. M. Brandza states that in plants where the ovule has two integu- 
ments, the constitution and origin of the envelopes of the seed have not 
been generally described. In most cases the internal integument is 
not consumed by the development of the embryo. It persists, and 
often constitutes the lignified part of the seminal envelope. Some- 
times the nucellus itself contributes to the formation of the envelopes of 
the ripe seed. It is only in certain families that the envelope of the seed 
* Atti R. Accad. Lincei (Rend.), vi. (1890) pp. 561-5. 
f Bot. Ztg., xlviii. (1890) pp. 337-45, 853-63, 369-79, 385-95, 401-9 (1 pi. and 
3 figs.). X Comptes Rendus, cx. (1890) pp. 1223-5. 
