ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 
617 
Morphological Origin of the Leaf.* — Dr. IT. Potonie discusses the 
derivation of the highly organised leaf of the higher plants from the 
simplest possible organisms, and points out the important part played 
by Goethe's theory of metamorphosis in the elucidation of the complicated 
problems of vegetable morphology. 
Leaves of Cupressineae.t — M. A. Daguillon adduces additional in- 
stances in support of his statement that the structure of the primordial 
leaves of many Coniferae — i.e. those which immediately succeed the coty- 
ledons — is intermediate between that of the cotyledons and that of the 
mature leaves in the characters already stated. This is brought out 
especially by a detailed description in the cases of Araucaria imbricata , 
Wellingtonia gigantea , Sequoia semper virens, Cryptomeria japonica, and 
Taxodium disticlmm, and of the genera Cupressus, Chamsecy paris, Biota , 
and Thuja. 
Leaf-primordia of Linaria spuria.^ — Prof. S. Scliwendener supports 
his theory of phyllotaxis, in reply to the objections of Vochting, by the 
observation that, in the leaf-shoots of Linaria spuria , there is an actual 
contact between the primordia of the leaves. The same is probably also 
true of the axillary flowering shoots. 
Stomates and their Subsidiary Apparatus. § — Herr M. Westermaier 
finds, in the guard-cells of stomates, two kinds of hinge, polar and dorsal 
hinges. The former, which have not previously been described, are 
important, and were found in a large number of Monocotyledons. In 
Echeveria ScheidecJceri the pair of guard-cells is surrounded by three 
subsidiary cells ; the latter have both dorsal and polar hinges, consisting 
of thin spots in the cell-wall. In Peperomia mag nolii folia the walls of 
the secondary cells are thin throughout. Polar hinges are especially 
characteristic of succulent plants. The tliick-walled surroundings of 
the stomates in the Cactese are described. The author further discusses 
the relation to classification of the various forms of stomate. 
Development of Hairs. || — Herr W. Hirsch classifies the hairs of 
plants under three heads, according as their growth is basipetal, acro- 
petal, or intercalary. The intercalary growth of hairs is uncommon, 
and may be combined with either of the other kinds. It occurs in Pole- 
momum coeruleum and Tragopogon Jloccosus. The mode of development 
ot the hairs by no means always followed the characters used in classifi- 
cation. This occurs especially with the Labiatse. 
Seedlings of Woody Plants.^ — Mr. F. Ramsley describes the struc- 
ture and development of the seedling in a large number of woody plants 
belonging to many orders of Dicotyledons. As a general result he 
states that a knowledge of the shape and general structure of the coty- 
* Naturwiss. Wochenschr., xiv. (1899) No. 35, pp. 405-15 (12 figs.). 
f Rev. Gen. de Bot. (Bonnier), xi. (1899) pp. 108-204 (1 pi. and 9 figs.). Cf. this 
Journal, ante, p. 29G. % SB. k. Preuss. Akad. Wiss., 1899, pp. 94-100 (1 pi.). 
§ ‘Ueb. Spaltoffnungen u. ihre Nebenapparate,’ 1899 (4 pis.). See Bot. Cen- 
tralbl., lxxix. (1899) p. 20. 
|| Beitr. z. wissensch. Bot. (Funfstiick), iv. (1899) l te Abt. See Bot. Centralbl., 
lxxix. (1899) p. 97. 
M innesota Bot. Studies, 1899, pt. ii. pp. 69-136 (8 pis. and 23 figs.). Cf. this 
Journal, 1893, p. 62. 
