No. 1, July, 1920] MORPHOLOGY AND IAXONOMY, ALGAE 155 



loiil. S( in LZ, A. Lathyrus montanus Bernh. mit verkiimmertem Oberblatt. [Lathyrus 

 montanus Bernh. with dwarfed blade and petiole.) Ber. Deul ch. Bol ' $6:572-674. L918. 

 — The plant examined has normally developed stipules bul much reduced Leaves. Not only 

 the leaf blade bul the petiole as well is dwarfed, attaining only half the size of the stip- 

 ules. Apparently there is a growth correlation between stipules and leaves! a1 least similar 

 anomalous structures have Keen reported by Goebel and others who found thai a reduction 

 in the size of the foliage leaves is accompanied by an increased development of the stipules. 

 In this case, however, the stipules remained normal as to size. — Ernst Artschwager. 



1005. SlNNOTT, E. W. Size variation in secondary xylem. [Rev. of: Baii.kv, I. \\\, AND 

 W. W. Tn-i'KK. Size variation in tracheary cells. I. A comparison between the secondary 

 xylems of vascular cryptogams, gymnosperms, and angiosperms. Proc. Amer. Acad. Arts and 

 Sci. 53:149-201. 6 fig. 191S.] Bot. Gaz. 67:374. 1919.— See Bot. Absts. 1, Entries 584, 

 99S. 



100t). Worsdell, W. C. The origin and meaning of medullary (intraxylary) phloem in the 

 stems of dicotyledons. II. Compositae. Ann. Botany 33:421-158. Fig. 1-27. 1919.— The 

 author's theory that the "internal-phloem" strands constitute an inner series of bundles 

 belonging to a fundamentally monocotyledonous type of vascular system is here applied to 

 the Compositae in particular and in general to most of the other orders of dicotyledons. 

 The vascular conditions in a large number of species belonging to many genera of Compositae 

 are described and may be summarized as follows: (1) The main vascular cylinder of the stem 

 is loosely constituted and the bundles are irregularly alined in the vascular ring; (2) The 

 occurrence of the medullary strands is highly variable; within the same genus they are pres- 

 ent in the stem of some species and absent in others; within the same species they are pres- 

 ent in some individuals and absent in others; in many cases they are completely absent or 

 very rudimentary in the stem but conspicuously present in the leaf; in many genera they are 

 entirely absent in all regions; (3) The degree of development of the medullary strands is also 

 variable; some are throughout well developed vascular bundles, some consist of phloem 

 only, while some exhibit both phloem and xylem in part of their course and in another part 

 phloem only; (4) In regard to the course (downwards) of the strands, some arise from flowers, 

 some from the vascular ring of the main stem, some from lateral branches and some de novo 

 in the pith; they may branch, fuse with one another or the main vascular ring, or die out 

 in situ. — From these and other facts the author draws the following conclusions: (1) The 

 intraxylary phloem of Compositae is a vestige of a formerly well developed system of medul- 

 lary bundles; (2) These bundles together with those of the vascular ring constituted a scat- 

 tered, monocotyledonous type of vascular system; (3) This monocotyledonous system was a 

 normal feature not only of this order, or its ancestors, but also of many other dicotyledonous 

 orders; (4) The conservative foliar organs often retain the ancestral condition when it has 

 become extinct or nearly so in the stem; (5) The Compositae as well as most other dicotyle- 

 donous natural orders have been derived from a monocotyledonous stock of geophytic habit. 

 — W. P. Thompson. 



1007. Yotjngken, Heber W. Notes on the dasheen and chayote. Amer. Jour. Bot. 6: 

 380-386. Fig. 1-5. 1919.— See Bot. Absts. 4, Entry 976. 



MORPHOLOGY AND TAXONOMY OF ALGAE 



E. N. Traxseatj, Editor 



1008. Allen, E. J. A contribution to the quantitative study of Plankton. Jour. Marine 

 Biol. Assoc. United Kingdom 12 : 1-S. 1919. — Briefly reviews the published work of others 

 and describes the application of the centrifuge and culture method, familiar to bacteriologists, 

 to the study of the diatoms, flagellates, etc. of the sea. By this means the author found 464 

 organisms, exclusive of bacteria, per cc. of sea-water, and concludes, since not all sea-organ- 

 isms will grow in the culture media employed, that the number present was probably nearer 

 1,000 per cc. — G. J. Pcirce. 



