No. 1, July, 19201 MORPHOLOGY, ETC., VASC. PLANTS 153 



don's supposition of growth acceleration as a physiological explanation for the stellate form 

 of the stele in young twigs. — //. C. Cowles. 



995. Denis, M. Recherches anatomiques sur quelques plantes littorales de Madagascar. 

 [Anatomical studies of some shore plants of Madagascar.] Rev. Gen. Bot. 31: 35-62, 115-120, 

 129-112. PI. l, fig. l-u. 191'.).— A detailed study of the ecological anatomy of a number of 



plants of the seashore sands of the eastern coast of .Madagascar. The climate is distinctly 

 tropical, with abundant sunshine, with a high, nearly constant temperature, moderate rain- 

 fall, and constant high, dry winds; the soil is a dry, loose sand. Under thee conditions the 

 majority of plants are characterized by an almost complete lack of special epidermal protec- 

 tion, by a fleshiness of loaf and sometimes of stem (which is, however variable), by a general 

 bifacial structure, and by well-developed water storage tissue. In these features, which are 

 practically typical halophytic modifications, these Madagascar plants approach the halophytes 

 of temperate regions. — A. J . Eames. 



99G. Evans, Arthur T. Embryo sac and embryo of Pentstemon secundiflorus. Bot. Gaz. 

 67 : 427-437. 1 pi. 1919. — The embryo sac is developed from a single megaspore, the antipodals 

 disorganizing early. The micropylar end becomes bulbous, the chalazal end long, narrow, and 

 covered by a distinct tapetum. The mature embryo sac is constantly gorged with starch, due 

 to the non-utilization of the nutritive materials which pass into the sac at a time of inactivity 

 just before fertilization. The endosperm nucleus immediately divides and free nuclei migrate 

 into the chalazal end of the sac, where wall formation begins. The proembryo is pushed into 

 this endosperm by an extreme growth of the suspensor. The micropylar end of the sac disinte- 

 grates. Two haustoria are formed, the micropylar by the growth of endosperm cells from the 

 chalazal end into the micropylar end, and the chalazal by the growth of endosperm cells 

 from the chalazal end out into the vascular system. The cells of the latter haustorium are 

 binucleate. False embryony occurs rather commonly. — Arthur T. Evans. 



997. Gatin, Valentine-Charles. Recherches anatomiques sur les variations du Paris 

 quadrifolia L. [Anatomical studies of Paris quadrifolia L. and its variations.] Rev. Gen. Bot. 

 31: 329-349, 353-371. Fig. 1-21. 1919. — The anatomy of the aerial stem, peduncle, and 

 flower of normal and abnormal forms is described, attention being given particularly to the 

 origin and course of the vascular bundles. The type with four leaves and a 4-merous flower 

 is considered normal. In this the essential structure is as follows: In the stem three series 

 of bundles persist without change from their points of origin at or near the rhizome to the 

 whorl of leaves; the outer two series supply the leaves and form an outermost series in the ped- 

 uncle. The innermost, or medullary, group becomes at the level of the leaves two concentric 

 series which pass directly into the puduncle so that the structure of the latter is similar to that 

 of the stem. Of the three series in the peduncle, the outermost is the sepal supply, the median, 

 the petal supply, and the innermost that of the stamens and carpels. In number and arrange- 

 ment of bundles the floral axis of Pan's is thus different from that of the majority of the Lilia- 

 ceae. Further, the vascular supply of the sepals, being derived from bundles distinctly foliar 

 in nature, has an origin quite different from that of the petals, which have a cauline supply; 

 and the supply of the stamens is derived independently of that of the petals, whereas the vascu- 

 lar supply of these two sets of organs often arises in common in the dicotyledons. From 

 a comparison of forms with abnormal numbers of leaves and of floral parts with typical 

 plants, it is found that the anatomical structure varies directly with external modifications. 

 The 3-merous forms approximate Trillium in structure, the 5- and 6-merous, the Asiatic spe- 

 cies of Paris. The author believes that there is evidence in this comparative study that a 

 trimerous type has been transformed into a tetramerous, and then into pentamerous and hex- 

 amerous types; that this process is now going on; and that the tendency toward this change is 

 spreading from the west to the east in the northern hemisphere. — A. J. Eames. 



998. Hardy, A. D. Teratological note. Pentamery in a flower of Narcissus. Proc. Roy. 

 Soc. Victoria 31 (N. S.), Part I: 7-8. 1918. [Received 1919.]— In Narcissus tazetta one bloom 

 among many thousands examined simulated a dicotyledonous bloom. The normal floral 



