ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 345 



Integument of the Seed of Impatiens.* — Pursuing his observations 

 on the structure of the seed of various species of Impatiens, M. C. 

 Brunotte finds it to illustrate a general fact that the integument of the 

 seed often presents a great variety of structure in plants belonging to 

 the same family, and even in species of the same genus nearly related 

 to one another. In the species of Balsamineae examined, this variability 

 applies 'especially to the external parts. The crushing up, at maturity, 

 of the inner integument appears to be a constant character, as well as the 

 presence of raphides and of mucilage. 



Ovary of Cytinus.f — M. L. Lutz records an abnormality in the ovary 

 of Cytinus Hypocystis, where the ovary, ordinarily unilocular with from 

 6-9 branching parietal placentas, has become plurilocular by the joining 

 of these placentas in the centre of the ovary, and the placentatiou axile. 

 This appears to be the archaic structure of the ovary, the unilocular con- 

 dition resulting from the gelification of the axis, the product of which 

 fills up the cavity in the form of gum. 



Placenta of Angiosperms.:J: —Prof. L. J. Celakovsky defends the 

 position he took up in 1876 that the placentae are always a portion of 

 the carpels, and that hence the ovules must always be regarded also as 

 products of the carpels, even in those cases where the ovule occupies 

 a terminal position at the apex of the axis, or where, from the elonga- 

 tion of the floral axis, a free central placenta is formed from which the 

 ovules spring. Iu other words, the apex of the axis from which the 

 placenta or the ovule arises, is not really axial, but belongs to the 

 e;. vsls. Among Pteridophytes Selaginella furnishes the only exception 

 to me derivation of the sporange from the rudiments of the carpols. 



Celakovsky reviews all the important subsequent literature on the 

 subject, and maintains that a study of abnormal structures shows the 

 incorrectness of Bower's view that sporanges are organs sui generis, 

 and cannot be transformed into vegetative organs such as leaves or 

 portions of leaves. 



The sporange (pollen-chamber, ovule) may have the value of a leaf 

 — which is rare, but occurs in Gymnosperms — or it may spring from a 

 sporophyll as a segment of a leaf. The caulome, consisting of all the 

 sterile segments of the axis, cannot produce a sporange. The growing 

 point of a shoot is not properly a caulome, but rather a thallome in 

 which the axis and leaves, with their potential archespores, are not yet 

 differentiated. 



Phylloclades.§ — Herr A. Schulz has investigated the structure and 

 function of leaf-like shoots, especially in Daitae racemosa, Ruscus acidea- 

 tus* R. Hypoglossum, and Asparagus officinalis. They result from an 

 excess of lateral shoots of normal origin in exceptionally crowded con- 

 ditions. They serve for assimilation or transpiration, or for the storing 

 up of reserve or nutrient substances, or as protecting organs. The 

 leaves have hence become superfluous, and have more or less entirely 

 disappeared. 



* Comptes Rendus, exxx. (1900) pp. 181-4. Of. this Journal, 1800, p. 435. 

 t Bull. Soc. Bot. France, xlvi. (1899) pp. 299-301 (5 figs.). 

 J SB. k. bohm. Gesell. Wiss., 1839, 35 pp. and 1 pi. 



§ 'Beitr. z. Eutwickgescli. d. Phylloeladien,' Rostock, 1898, 40 pp. and 20 figs. 

 See Beih. z. Bot. Centralbl., ix. (1900) p. ITS. 



