356 Morphologie, Teratologie, Befruchtung, Cytologie. 



of these is that two daughter nuclei in the telophase, between 

 which no wall-formation is in progress, are often found enclosed in 

 a hollow sphere of dense and deeply-staining cytoplasm. — the 

 appearance at first sight suggesting a cell within a cell. This cy- 

 toplasmic shell has been observed in 35 species belonging to 17 

 natural orders. 



The authors point out that this paper is merely a preliminary 

 survey of results which they hope to deal with more fully in a 

 later raemoir. Agnes Arber (Cambridge). 



Boeuf. Formes teratologiques chez Hordeian vulgare. {Assoc. 

 fr. Avanc. Sc. Congres de Tunis. 1913. p. 301 — 303. fig. Paris. 

 1914.) 



Une ramification insolite est observee dans la tige, l'epi, Fepil- 

 let. Ces diverses modifications peuvent se combiner. Elles semblent 

 etre hereditaires et independantes des conditions exterieures. 



P." Vuillemin. 



Boeuf. Polymorphisme du Chrysanthemum coronarium. (Assoc. 

 fr. Avanc. Sc. Congr. de Tunis. 1913. p. 293—295. Paris, 1914.) 



Dans les plantes sau vages des environs de Tunis, l'auteur 

 Signale des variations, dont 5 interessant la forme des ligules, 8 

 interessant leur coloration. Les graines tombees autour d'un pied ä 

 feuilles frisees ont donne des pieds dont une partie avait des feuilles 

 frisees. P. Vuillemin. 



Lignier et Mail. A propos d'un Gui [Viscum album L.) en 

 palmette. (Assoc. fr. Avanc. Sc. Congres du Havre. 1914. p. 

 439—442. Paris 1915.) 



Dans un Viscum album ayant pour höte un Crataegus Oxya- 

 cantha, expose aax embruns marins dans un sol crayeux, les con- 

 ditions defavorables de la Vegetation entrainentun exces de floraison 

 au detriment des bourgeons qui, d'habitude, s'allongent. 



P. Vuillemin. 



Pickett, F. L., The development of the embryosac of 

 Arisaema triphyllum. (Bull. Torrey Bot. Club. XL. p. 229—235. 

 PI. 13, 14. 1913.) 



The development of the embryo sac of Arisaema triphyllum 

 was first studied by Strasburger and later by Mottier. Camp- 

 bell used these studies as a basis for comparison and Gow added 

 observations of the division of a primary archesporial cell to form 

 embryo-sac Initials. 



The present study has verified most of the findings of other 

 investigators. but has given results at variance with their reports 

 in regard to the following points. 



a) The origin of the several megaspore mother cells from a 

 Single primary archesporial cell is doubtful. 



The first division in the formation of the tetrad has been pro- 

 bably mistaken by earlier investigators for a division of a primär}?- 

 archesporial cell into embryo-sac Initials. 



b) The formation of a tetrad of potential megaspores from some 

 of which the embryo-sac or sacs develop, instead of from an arche- 

 sporial cell, is shown. 



