ZOOLOGY AND BOTANY* * * § MICROSCOPY, ETC. 
97 
tinguished from one another, special attention being given to the micro- 
scopic structure of the stem and leaves, which are profusely illustrated, 
and to the chemical composition. 
Morphology of Aquatic Plants.* — Pursuing his investigations on 
this subject, Herr W. Wiichter finds that, in the Nymplueacem, the rela- 
tionship of the submerged to the floating leaves is the same as that of 
the narrow primary leaves to those which have a broad lamina in the 
monocotyledonous aquatic plants already examined. Both kinds un- 
doubtedly originate from leaf- rudiments which are morphologically alike. 
Whether the rudiment develops into a submerged or into a floating leaf 
depends on external conditions such as the supply of food-material ; the 
submerged leaves represent an arrested stage of growth. 
Anatomy of Phrymacese, Stilboideae, Chloanthoidese, and Myo- 
poraceae. j* — Dr. J. Briquet gives further details of his researches into 
the anatomy of these orders and families. The Phrymaceae agree, in 
the general structure of their vegetative organs, with the Labiatae, and 
with some families of Verbenaceas with opposite leaves. They differ 
widely from the Myoporaceae in the course of the vascular bundles, and 
in the presence, in the latter order, of secreting pockets. The Stilboideae 
do not differ, in any essential point, from the other tribes of Yerbenaceae. 
The Chloanthoi'deae, another tribe of Yerbenaceae, display far less uni- 
formity of structure than the Stilboideae. The hairs, when present, 
are invariably branched. As regards the classification of the genera 
of Myoporaceae, Ofiia must be placed by itself in a separate tribe, dis- 
tinguished by the absence of secretory pockets. J 
Dimorphism of Ranunculus Ficaria.§ — Prof. F. Delpino calls atten- 
tion to the fact that this common plant is dimorphic (gynodioecious), 
one form being hermaphrodite, the other female ; and the two are readily 
distinguished from one another by the size of the flowers. Besides 
having larger flowers (in the proportion of about 3 : 2), the hermaphro- 
dite flowers are distinguished by having a larger number of petals 
(8-11 instead of always 8 in the female), a larger number of stamens 
(those of the female flowers being functionless), and a larger number 
of carpels. There do not appear to be intermediate stages between the 
two forms. 
Morphology and Anatomy of the Nymphaeaceae.l] — Mr. D. T. 
Gwynne-Yaughan has investigated several points in the morphology of 
the leaf, the anatomy of the mature rhizome and of the seedling, the 
apical meristem, the insertion of the adventitious roots, and the occur- 
rence of polystely, in various genera of Nymphasaceae. The leaf of the 
mature plant passes, in its youth, through stages which are quite parallel 
to those permanently retained by the embryonic leaves. The number of 
bundles in a stele varies between a large number in Victoria and only 
two in Cabomba and Brasenia. The simplicity of the anatomical struc- 
ture in these two genera corresponds to the structure of the flower ; 
* Flora, Ixxxiv. (1897) Erganzbd., pp. 343-8. Cf. this Journal, 1897, p. 405. 
f Mem. Soc. Phys. Hist. Nat. Geneve, xxxii. (pt. 2), 1G3 pp. (29 figs.). Of. this 
Journal, 189G, p. 537. J Cf. this Journal, 1897, p. 48. 
§ Atti r. Acvad. Sci. 1st. Bologna, 1897, pp. 685-710. 
|| Trans. Linn. Soc., v. (1897) pp. 287-99 (2 pis.). 
1898 
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