278 MORPHOLOGY, ETC., VASC. PLANTS [Box. Absts., Vol. X, 



1827. Langdon, LaDema M. Storied structure of dicotyledonous woods. [Rev. of: 

 Record, S. J. Storied or tierlike structures of certain dicotyledonous woods. Bull. Torrey 

 Bet. Club 46: 253-273. 1919 (see Bot. Absts. 3, Entry 2442).] Bot. Gaz. 69: 270. 1920. 



1828. Lansdell, K. A. Weeds of South Africa. I., II. and III. Jour. Dept. Agric. 

 Union of South Africa 2: 315-321. Fig. 1-11; 2: 541-551; 3: 172-177. Fig. 12-59. 1921.— 

 General descriptions and illustrations are given of the morphology of flowers, fruits, and 

 leaves of South African weeds. — E. M. Doidge. 



1829. PuJiULA, J. Contribucion al conocuniento anatomicofisiologico de los zarcillos de 

 la zarzaparrilla (Smilax aspera). [Contribution to the knowledge of the anatomy and physiology 

 of the tendrils of Smilax aspera.] Broteria S6r. Bot. 19: 66-72. Fig. 1. 1921. — Contact 

 irritability in the tendrils of Smilax aspera seems a general function of the epidermal cells, 

 no special correlated structures being visible in microscopic sections. Such sections, how- 

 ever, show great and irregular thickenings of the transverse cell walls, the lumen at times 

 being wholly filled; this is true even of the guard cells of stomata with an apparent loss of 

 function. The author concludes that the thickening is in response to mechanical stresses 

 after the tendril has secured support, and that coincidentally ability to respond to stimulation 

 is lost. — E. B. Chamberlain. 



1830. Show ALTER, A. M. An orthotropous ovule in Hyacinthus orientalis L. Torre3'a21: 

 62-63.' Fig. 1-2. 1921. — An ovule in the upper part of an ovary was found to be orthotropous 

 instead of anatropous, but tj^jical in all other respects. In the median portion of the ovary 

 the carpels seemed to be imperfectly fused and the placentas slightly displaced. — /. C. Nelson. 



1831. SuESSBNGTjTH, Karl. Beltrage zur Frage des systematischen Anschlusses der 

 Monokotylen. [Contributions to the systematic relationships of the monocotyledons.] Beih. 

 Bot. Centralbl. 38: 1-79. Fig. 1-18. 1921. — The following criteria are considered important 

 in deciding the relationships of the monocotyledons: (1) Microspore development, peri- 

 plasmodium; (2) development and structure of the embryo-sac and young ovules; (3) endo- 

 sperm and perisperm; (4) embryo; (5) flower structure; (6) bundle structure and arrangement 

 and cambiiun; (7) leaf structure; (8) root structure; (9) serum reaction. — After the heterotypic 

 division in monocots, the daughter cells develop walls, whereas in dicotyledons walls appear 

 only after the 4 nuclei are formed. These are known respectively as the successive and 

 simultaneous methods of pollen formation. The latter is phylogenetically the older as it is 

 found in Gymnosperms and commonly in pteridophytes and mosses. The embryo sac and 

 megaspore do not seem to furnish any distinctive characters for either group. Besides a 

 comparison of those already investigated, the author studied Dioscorea, Tacca, Cyperus, 

 Hydrocleis with normal sacs, and Chamoedorea with a 4-nucleate sac. Most monocotyledons 

 and many of the choripetalous and some of the sympetalous dicotyledons have endosperm 

 showing free simultaneous division, — Palm's "nuklearem" type. Monocotyledony is con- 

 sidered as ecologically induced. The flower structure is probably the most important reason 

 for regarding the group as monophyletic. — L. Pace. 



1832. Thoday, Mary G. Ripening of seed in Gnetum gnemon and Gnetum africanum. 

 South African Jour. Sci. 17: 189-192. 2 fig. 1921. — The structure of the mature seed is of 

 interest ontogenetically in showing a method of closing the pollinated ovule of a gymnosperm. 

 It is also of importance in connection with the comparison made between the seeds of the 

 Gnetales and those of the Bennettitales. — E. P. Phillips. 



1833. Wager, H. A. The leaves of Hakea pectinata and H. suaveolens. South African 

 Jour. Sci. 17: 284-286. 2 fig. 1921. — The leaf of the former species has probably evolved on 

 xerophytic lines from a flat, more expanded, and delicate type. The latter species still shows 

 xerophytic characters, such as toughness, thick cuticle, and sunken stomata. This is con- 

 sidered as a case of reversion in that the type of leaf found in H. suaveolens has evolved from 

 that of H. pectinata. — E. P. Phillips. 



