Botany. 
237 
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brown horny margin, set off by the large light red-brown spines, 
is thought to be one of the finest of the genus for ornamental cul¬ 
tivation. It was discovered by Dr. Parry in 1850, but good 
specimens only now obtained, and it is appropriately dedicated to 
the founder of the Missouri Botanic Garden, from which much is 
confidently expected. Finally, there is a division known by the 
tube of the perianth equaling the lobes or hardly shorter, and 
bearing the stamens: to this belong A. rigida Miller, with the 
Yucatan doubtful variety, Sisalana , introduced nearly forty years 
ago into S. Florida by the unfortunate Dr. Perrine ; A. Palmeri , 
n. sp., from S. Arizona; and A. Wislizeni , n. sp. (which has had 
the utterly false name of A. scabra in Germany) in Northern 
Mexico. A reference to one or two very imperfectly known spe¬ 
cies is appended. Of A. Americana , there is a mere mention 
that it has a stipitate capsule. 
In all species, so far as known to Dr. Engelmann, the anthers 
discharge their pollen about forty-eight hours before the style 
matures and the stigma can receive pollen. After the expansion 
of the lobes of the latter, at least in A. Virginica, a viscid liquid 
fills the cavity of the apex of the style, “ whether stigmatic, or 
on y intended to allure insects, has not been ascertained.” The 
figures which so commonly represent bursting anthers and a fully 
elongated style in the same blossom are probably factitious, as 
they certainly are in many otherwise excellent plates of various 
kinds of flowers. In conclusion, those who have the opportunity 
to examine species of Agave in flower are particularly requested 
to note at what hour of the day the anthers begin to shed their 
pollen, and at what time they become effete, and in what state 
the style is at these periods. The anthesis, so far as Dr. Engel¬ 
mann has observed, is vespertine or nocturnal, as well as proter- 
androus. The time and nature of the nectariferous secretion in 
the lower part of the flower should also be recorded. a. g. 
2. Structure of the Learns of Grasses: Histotaxie des feuilles 
de Gramine'es ; par J. Duval-Jouve.— An elaborate article in 
Ann. Sci. Nat., tome i, of Ser. 6, 1875, with four admirable plates 
of anatomical details. It appears to be an excellent piece of work, 
upon an almost neglected subject. Many of the text-books still 
say of the leaves of grasses, and indeed of Monocotyledons gen¬ 
erally, that their veins or nerves are simple and unconnected by 
anastomosis; although what was meant must have been that the 
only anastomosis was by ultimate transverse veinlets. Duval- 
Jouve cites a long list of grasses in which these are conspicuous; 
and there are many in which the reticulating veinlets are of different 
orders. The stomata of grasses are in some confined to the lower 
surface of the leaf; in others divided between the two faces; in 
several they are restricted to the upper face, but in these the blade 
makes a turn or twist, so as for the most part to present this upper 
surface to the ground. Triticum junceum, Calamrogastis ( Psam- 
ma) arenaria , and Gynerium argenteum (Pampas Grass) are cited 
as instances. Many grasses have under the epidermis of their upper 
2 3 4 5 6 7 8 9 10 Misso 
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