PHANEEOGAMIA. 
601 
Miquel, E. A. W.—Mora Brasiliensis, fasc. 32. Sapotaceae. With 
33 plates. The new genera are Passaveria (Fcclinusa, olim Hb. 
Mart. Bras.), with the facies of Lucuma and flowers of Chryso- 
phyllum , and Oxythece , Miq. with the flowers of the latter, and 
habit of Sideroxylon, but with exalbuminous seeds. 
-- Bemarques sur la genre Nania. Miq. Journ. Bot. i. 292. 
With 1 pi. Nania is a genus of Myrtaceae, with the habit of 
Eucalyptus , but with tetramerous flowers, and an ovary almost 
free, growing in the Indian Archipelago. It is based on Metro- 
sideros vera, D.C. 
*—-Over die geographische verspreiding der Mceae, met een 
nader onderzoek omtrent de soorten, welke in America, noordelijk 
van de landergte van Panama, voorkommen. Amsterd. Yersl. 
K. Ak. 1862, xiii. p. 382. 
Moiil, Hein.—M orphologische IJntersuchungen liber die Eiche. 
Cassel. 1861. pp. 35. 4to. 3 plates. 
Mohl, H. v.—Einige anatomische und physiologische Bemerkungen 
iiber das Holz der Baumwurzeln. B. Z. 1862, p. 225 continued to 
321. Upon the ill-understood structure of the roots of trees, and 
the relation of their structure to that of the trunk. Coniferae and 
deciduous trees are treated separately; Abies pectinata being 
selected as presenting the characteristic distinctions of root and 
stem-structure most plainly in the former—the Ash, Fraxinus 
excelsior, among the latter. Special reference is made to certain 
errors of Schacht’s (Anat. u. Physiol, d. Grewachse) as to the 
above. The root of the Abies differs from the stem in the follow¬ 
ing particulars:—1. In the smaller thickness of the annual zones 
and greater softness of the wood. 2. In the opposing structure 
of thick and thin zones. In the stem the outer portion of the 
annual rings, consisting of thick-coated cells, is the wider, the 
narrower the entire zone, while in the root the conditions are re¬ 
versed ; the more solid portion of the zone being thicker in thin 
rings ; when they are very thin it almost entirely disappears. 3. 
In about one-fourth greater radial and one-fifth greater tangential 
diameter of the wide cells of the inner portion of the annual 
zones ; and, 4th, the greater radial diameter, and broader cavity 
of the outer cells. 5th. The greater length of the cells of the 
innermost, soft portions of the root. Modifications of the above 
relations are detailed in Finns sylvestris , Larix europea , and 
Ficea vulgaris. In the Ash the greater or less thickness of the 
annual rings is accompanied by corresponding and very con¬ 
siderable differences in their structure. These differences, in the 
layers making up each ring, are described. The rings of the stem 
are usually thicker than those of the root, while the wood of the 
latter is softer and more spongy; the cells being broader and 
with thinner walls. Modifications of structure are described in the 
Beech, Oak, Birch, Aspen, and Barberry.—P. 258 et seq. the 
principal contrasts of root and stem-structure are reviewed. The 
