8CIENTIFIC SUMMAKT. 
307 
rate memoir upon this family. He enumerates 260 species, of wLicli one 
hundred are new or not previously described. Of the five genera recognised, 
Tetraclis has been established for an undescribed Madagascar plant in the 
Paris Herbarium. The order has its focus in the East Indies, where 86 
species of Diospyros and 19 of Maha occur ; Euclea and Royena are confined 
to Africa. It is interesting to note that the order is unrepresented in New 
Zealand, Tasmania, and the Andine region — countries the vegetation of 
which has many interesting points of contact. Generally speaking, Ebenacece 
are strongest in the tropics in both the old and new worlds. Diospyros 
lotus is an Asiatic species naturalised along the Mediterranean; D. vir- 
giniana, wliich is well known in the United States as Persimon, is nearly 
allied. Throughout the memoir any tendency to do more than carefully 
ascertain facts has been studiously suppressed. This becomes somewhat 
tantalising in the account of the supposed fossil species. The author has 
been at the pains of drawing up a clavis of all the fossil remains which have 
been assigned to this order, good, bad, or indifferent — including even those 
for which it appears to him that Ebenacce is not the probable family. 
Silicijied Plants of the Coal Measures. — Among the silicified vegetable 
remains from the Coal Measures found in the soil near Autun, occur amor- 
phous siliceous masses which enclose small fragments of the stems, roots, 
and other parts of plants, mostly Cryptogams. M. B. Renault, continuing his 
researches upon these interesting remains, refers (“Comptes Rendus,” 1873, 
part 13, 811, The Academy, May) some of the small detached stalks to the 
imprints known as Sphenophyllujn. They are from three to fifteen mm. in 
diameter, and present on the exterior nodes which correspond to leaf-whorls, 
as in Sphenophyllum. In the centre is a vascular axis of a triangular form 
consisting entirely of tubes diverging from the centre, scalariform or spiral 
at the angles, where they surround a cylindrical lacuna. This axis is en- 
closed by a tissue resembling that surrounding the vascular bundles in ferns 
and some Lycopods. Outside of this, the ligneous axis of M. Renault, 
are layers of cellular tissue belonging to the bark, which are traversed by 
eighteen vascular bundles proceeding towards the leaves. The nodosity of 
the stems and the verticillate disposition of the appendicular organs, as well 
as the probable number of these parts, are points of resemblance with Spheno- 
phyllum, while their internal structure indicates the relations of these plants 
to the Lyeopodiacece and Marsileacece. M. Renault also describes the struc- 
ture of a fragment of a silicified fructification spike, referred to Annularia 
longifolia and found in the same place. The stem is thick and slightly striated, 
bearing whorls of bracts, very different from the leaves of the sterile branches. 
Alternating with these are whorls of pedicels, to which are attached two 
sporangia, above and below ; these occupy the whole space between the 
pedicel and the bract, and contain a large number of minute spherical spores. 
The axis of the fruit spike shows a broad central lacuna surrounded by a 
lengthened cellular tissue, containing from sixteen to twenty cylindrical 
lacunae placed at regular distances apart. 
The Fovilla of Pollen. — Signor Saccardo states in the Nuovo Giornale 
Botan. ItaL,” that botanists are agreed that the minute grains in the con- 
tents of pollen consist of starch -granules, oil-globules, sugar, and nitro- 
genised compounds, but, so far as he is aware, no observer has yet noticed 
X 2 
