80 Miscellaneous. 
mentation, which induce him to adopt the notion of M. Schultze, 
that segmentation is due to a contractility of the vitellus.—Bericht 
der Akad. der Wiss. zu Wien, 28 April, 1864, p. 75. 
On globular Cell-thickenings in the Envelope of the Roots of some 
Orchidee. By Dr. H. LeirGes. 
The cellular stratum beneath the envelope of the aérial roots of 
tropical Orchideze always consists of two kinds of cells—namely, 
elongated and usually thick-walled cells, and shorter ones which are 
always thin-walled. The walls of the cells of the root-envelope adja- 
cent to this stratum are always thickened in a peculiar manner, and 
the structure of these strata of thickening, again, is usually different in 
the walls situated upon the thin-walled cells and in those adjacent to 
the elongated cells. On the former several superimposed strata may 
not unfrequently be recognized ; and these, in some plants belonging 
to the genus Sobralia, acquire so great a development as to form 
pretty large spherules, often occupying nearly the whole cell. Oude- 
mans, who first mentioned these spherules, regarded them as foreign 
bodies ; but, from careful anatomical investigation, as also from their 
behaviour with reagents, they must be regarded as accumulated 
thickening layers—a view which is also established most indubitably 
both by the history of their development and by comparison with 
other similar structures. From the circumstance that these spherules 
are produced by the superimposition of several thickening layers, 
each of which proves to be a network formed of numerous inter- 
crossing fibres, we must ascribe to them a porous character, and it 
is probably in this property that their physiological significance 
consists. Thus, as porous bodies, they have the power of taking up 
the water condensed by the envelope of the root, and of retaining it 
for a considerable time, so as to furnish it gradually to the subjacent 
conical (thin-walled) cells; in this way they acquire, to a certain 
extent, the function of reservoirs of water, which are necessary for 
these plants, as they do not grow in moist primeeval forests, but in 
the open ground, and throw out their roots upon the surface of the 
sandy soil.— Bericht der Akad. der Wiss. zu Wien, 10 March, 1864, 
p. ol. 
Notice of a new Squirrel from Natal. By Dr. J. E. Gray, F.RS. &e. 
ScIURUS ORNATUS. 
Back dark blackish grizzled ; hairs red, with a broad black sub- 
terminal band and a white tip. Head, legs and thighs, underside, 
and tail very bright red-bay ; the hairs of the head, limbs, and belly 
red to the base; the hairs of the tail very vivid and dark red for 
more than half their length; the base, especially of those near the 
lower end of the tail, black, with two broad greyish bands. 
The red colour of the female not quite so bright and dark, and 
the base of the tail grizzled, with shorter red tips to the hairs. 
Hab. Natal (W. Fosbrooke, Esq.). 
This species is about the size of the Common European Squirrel. 
—Proc. Zool. Soc. Jan. 12, 1864. 
