1885.] Botany. 799 
structural formulz for certain silicate minerals which are most 
interesting if demonstrable-—Tiffany & Co., of New York, have 
just published an illustrated catalogue of their collection of rough 
diamonds which so admirably exhibits all the phases in the crys- 
tallography of this interesting mineral. The collection embraces 
904 stones weighing over 1876 karats, of these twenty-two are in 
the rock.———Dr. Konrad Uebbeke,’ of Munich, has published 
some studies made upon crystallized minerals found in the ande- 
sites of Mt. Dore in Central France. Hypersthene, hornblende 
and pseudo-brookite receive especial attention.—— K. von 
Chrustschoff? in the second part of his paper on secondary glass- 
inclusions finds that those observed in quartz fragments which 
have been imbedded in a liquid magma are due in all cases either 
to the infiltration of this magma into fissures or to the melting of 
some more easily fusible mineral which existed as an inclusion in 
the quartz before its imprisonment. in the magma. Professor 
Roland Irving, of Madison, Wis., in charge of the U. S. Geologi- 
cal Survey of the Archzan rocks of the Northwest, has just 
issued a most interesting paper on secondary enlargements of 
mineral fragments in certain rocks.* A large number of observa- 
tions show the widespread growth of rounded quartz grains by 
subsequent deposits of silica, which acts as their cement. This 
phenomenon, which was first described by Sorby and has since 
received considerable attention from A. A. Young, Irving, and 
others, plays a most important rôle in the change of sandstones 
to quartzites. The enlargement in the same manner of feldspar 
grains by secondary deposits of feldspar substance was recently 
observed for the first time by Professor C. A. Vanhise, of Madi- 
son, whose paper’is appended to the present work. The facts 
i d are illustrated by a large number of excellent colored 
plates. ~ 
BOTANY.‘ 
RANCHING OF PTERIS AQUILINA.—Much has been written on 
the structure of this well-known fern, but the relation of the 
fibro-vascular system of the stipe to that of the rhizome does 
not seem to have been traced. The widely-creeping rhizome A 
contains at the center two strong bands of sclerenchyma with two 
fibro-vascular bundles or rows of bundles between them, the 
whole surrounded by a ring of bundles much as in Fig. 1 B. In 
branching division occurs on a line crossing both bands of scleren- 
chyma, setting off to the branch a portion of both central bundles 
1 Bull. Soc. min. de France, 1885. 
2 Tschermak’s Min. und Pet. Mitth., vis, 1885, p. 64. 
_§ Bulletin of the U. S. Geol. Survey, No. 8. Washington, Govt. printing office.” 
1884. (Price ten cents.) ` 
* Edited by Professor CHARLES E. Bessey, Lincoln, Nebraska. 
