ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
403 
Abnormal Formation of Resin-Ducts.* * * § — Dr. A. P. Anderson de- 
scribes the conditions under which resin-ducts are formed abnormally in 
Conifers. This may be due either to the effects of frost, or to the attacks 
of AEcidium elcitinum , the fungus which produces “ witch-broom,” or to 
infection by other fungi, such as Agaricus melleus, Phoma abietina, and 
Pestalozzia Hartigii. He regards the resin as in all cases an excretory 
product, haying no further use in the metabolism of the plant. When- 
ever resin-reservoirs are found in the wood of Abies pectinata , they are a 
sure indication of some pathological condition existing in the plant. 
Anatomy of the (Enotherege and Haloragese.f — A study of the 
anatomical structure of the stem and leaves leads M. P. Parmentier to 
divide tho order Onagraceae into the two families (Enotheraceae and 
Haloragaceae — the former being again subdivided into the Ludwigieae 
and the (Enotliereae ; the latter into the Halorageae and the Gunnereae. 
Details are given of the histology of each genus. Gayophytum and 
Glarkia are sunk in (Enothera , and Jussisea in Lndwigia ; while Scliizo- 
carya is separated generically from Gaura. There are distinct modes 
of crystallisation of the calcium oxalate characteristic of the two fami- 
lies (Enotheraceae and Haloragaceae. Ludwigia possesses both kinds. 
Another difference between the two families is in the nature of the 
hairs. The root of Gunnera presents a remarkable peculiarity in having 
secondary vessels enclosed in its pith. Stomates occur on both surfaces 
of the leaf, even in the aquatic species. 
(4) Structure of Org-ans. 
Relationship between the Structure and Function of Organs*! — 
Herr Rosen gives a brief resume of the facts respecting the degeneration 
or other modification of the floral and vegetative organs of plants, and 
their consequent adaptation to special functions. 
Position of Dorsiventral Organs.§ — From an examination of the 
forces which determine the position of leaves in a number of plants, 
Mr. R. N. Day derives the following conclusions : — The prevalence of an 
epinastic or hyponastic condition in any organ is due entirely to inde- 
pendent causes, and may be said to be spontaneous. In many plants 
leaves are epinastic in an earlier- and hyponastic in a later period of 
growth, or vice versa. It is entirely independent of light ; there is no 
such thing as photo-epinasty. All dorsiventral leaves are diaheliotropic. 
They may be either diageotropic or apogeotropic. The position of the 
organ is determined by the relative intensity of the geotropic and the 
trophic forces acting upon it. 
Development of the Flower. || — Prof. L. J. Celakovsky traces the 
phylogenetic development of the flower of Phanerogams from the sporo- 
phyll of the Lycopodiaceae and Equisetacese. The lowest stage is seen 
in the flower of the Gymnosperms, — naked in the Cycadeae and Coniferae, 
* Forst.-naturw. Zeitschr., 1896, 38 pp. and 7 figs. See Bot. Gazette, xxiii. 
(1897) p. 292. f Ann. Sci. Nat. (Bot.), iii. (1896) pp. 63-149 (6 pis.). 
t J-B. Schles. Gesell. vaterl. Cultur (No. 71); Bot. Sect., pp. 33-42. See Bot. 
Centralbl., lxx. (1897) p. 125. 
§ Minnesota Bot. Studies, 1897, pp. 743-52 (1 pi.). 
H S.B. K. Bohm. Gesell. Wiss., 1896, 91 pp. and 4 figs. 
