Descendenz und Hybriden. — Morphologie und Teratologie. 171 



White, C. A., The Relation of Phylogenesis to Historical 

 Geology. (Science. N. S. XXll. 1905. p. 105—113.) 



The author considers that geological evidence shows the origin 

 of species by natural selection, to be unsatisfactory and inconsistent 

 with the observed abruptness with which new groups arise in a 

 given geological age; while the assumption of an illimitably remote 

 period for the beginning of life, which natural selection requires, is 

 opposed by physicists as inconsistent with cosmical law. On the 

 other band, all observed facts are consistent with and may be satis- 

 factorily explained by reference to the Mutation Theory as advanced 

 by de Vries. D. P. Penhallow. 



Armour, Helen M., On the Morphologyof Chloranthus. (New 

 Phvtologist. Vol. V. No. 3. 1906. p. 49—55. With plates III 

 and IV.) 



Three species of Chloranthus are described : C. chinensis, C. 

 officinalis and C. brachystachys. The flowers consist of a staminal 

 Scale inserted on a unicellular ovary. This scale in C. chinensis 

 and in C. officinalis bears eight pollen sacs and is supplied with 

 three vascular bundles; in C. brachystachys six bundles enter the 

 flower, four passing to the ovary and two to the staminal scale. 

 The ovule arises on the adaxial wall of the ovary; the multicellular 

 archesporium cuts off the primary tapetal cells which form a cap 

 over the sporogenous tissue. The lowest cell of the central column 

 of cells in the sporogenous mass becomes the embryo-sac mother 

 cell; this divides into four cells and one of these forms the embryo- 

 sac, the developement of which is normal. Three layers can be 

 disiinguished in the fruit: the outermost fleshy coat is derived from 

 the carpellary wall, the outer integument forms the hard fibrous 

 layer, and the inner integument is represented by a layer of thin 

 walled tissue. The embryo, which is embedded in the endosperm, 

 is small and shows no differentiation of parts. A small scale occurs 

 at the base of the staminal scale of C chinensis and C. officinalis, 

 but is absent in C. brachystachys. It contains no vascular tissue and 

 drops off after fertilisation. It may be regarded as an outgrowth 

 Standing in relation to the rapid widening out of the staminal scale 

 above its narrow insertion. 



The examination of these species supports the view that the 

 flower is hermaphrodite. The vascular supply of the staminal scale 

 of C. chinensis is consistent with the view that the scale corresponds 

 to three stamens, the middle one bearing two anther lobes and the 

 lateral ones being reduced. The two pairs of pollen sacs in 

 C. brachystachys may correspond to the reduced lateral stamens of 

 C. chinensis. The author concludes that the Chloranthaceae is a 

 group of the Piperales presenting in some points, and especially in 

 the structure of the ovule, primitive characters in common with the 

 majority of the Archichlamydeae, while in other respects special 

 modifications of the flower are shown. M. Wilson (Glasgow). 



Campbell, D. H., Studie s in the Araceae. III. (Annais of Botany. 

 Vol. XIX. No. LXXV. 1905. With plates XIV— XVII. p. 329-349.) 



The plants studied are Anthuriiun violaceuni Schott, var. leuco- 

 carpiim and Nephthytis Liberica Schott. \r\ A. violaceuni the number 

 of chromosomes in the pollen mother cells is sixteen. The arche- 

 sporium consists of a single sub-epidermal cell, and, on division, a 



