ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
3(37 
distinct hypoderm. In drupes the flesh is rarely homogeneous ; when 
heterogeneous, it may be formed of one, two, or three layers. The stone 
is composed, independently of the fibrovascular bundles, of five distinct 
elements, viz. sclerotic cells properly so-called, sclerotic fibres, sclerotic 
tabular cells, sclerotic tubular cells, and parenchyme. The development 
of these various elements is traced ; and a large number of examples are 
then described in detail, as regards both the ovary and the mature fruit. 
Integument of the Seed of Cyclospermae.* * * § — M. L. Meunier has 
made an exhaustive examination of the structure and development of the 
integument of the seed of the Cyclospermae (Chenopodiaceae, Phyto- 
laccaceae, Aizoacese, Illecebreae, Portulacacese, and Caryophylleae), 
characterized by having a curved embryo buried in a copious endosperm. 
He distinguishes two types, viz. : — (1) The chenopodic type (Cheno- 
podiese, Baselleae, Amarantheae, Gomphreneae, and Celosieae). The 
membrane of the cells, which are in general prismatic, takes, exclusively 
of its external surface, a thickening which is often considerable, and is 
composed of a number of bars, usually parallel, having their base in the 
external cuticle, and descending more or less deeply into the secondary 
membrane. The same type occurs with modifications also in the 
Aizoaceas, Illecebraceae, Phytolaccacese, and Portulacaceae. (2) The 
caryophyllic type (Caryophylleae). The epidermal cells have a wavy 
and not a polygonal outline, and the cuticle is often remarkably 
sculptured. The outer membrane has not the stalactite structure of the 
Chenopodieae, but is remarkably thick, and is furnished with singular 
prolongations of cellulose which descend into the cell-cavity. The 
variations of these two types are described in detail in all the genera 
included in the group. 
Stomates.j — Prof. A. Weiss gives details of the distribution, form, 
and measurements of the stomates in several hundred species belonging 
to a great number of different families. 
Rudimentary Stomates in Aquatic Plants.^— M. C. Sauvageau 
describes structures which occur frequently in the leaves of aquatic 
plants, both freshwater and marine, similar to those already known in 
the case of Callitriche. They consist of a depression on the upper side 
of the leaf near the apex of the mid- vein, which places the inner con- 
ducting system in connection with the external air, and which may be 
regarded therefore as aquiferous stomates. They are formed by the 
separation of epidermal cells, and occur in all species of Potamogeton 
examined, in Zostera , Halodule , and PJiyllospadix , but not in other 
marine genera. 
Metamorphosis of Vegetative Shoots in the Mistletoe.§ — Herr E. 
Loew describes two abnormal metamorphoses of vegetative shoots into 
flowers in the mistletoe. In the first the three-flowered axillary shoot 
was suppressed, and in its place the foliage-leaves and bracts had become 
transformed into perianth-leaves. In the second instance the two lateral 
* La Cellule, vi. (1890) pp. 299-392 (7 pis.). 
f SB. K. Akad. Wiss. Wien, xcix. (1890) pp. 307-82 (2 pis.). 
X Comptes Rendus, cxi. (1890) pp. 313-5. 
§ Bot. Ztg., xlviii. (1890) pp. 566-73 (2 figs.). 
2 C 2 
