626 Anatomie. — Morphologie etc. 



In the Umhelliferae also, the parenchyma is vasicentric and the 

 end walls of the vessels have simple pores, vvhich are nearly round 

 and nearly at right angles to the lateral walls. 



General anatomical features would lead to the retention of the 

 sub-families Nyssoideae and Davidiodeae in the Cornaceae and would 

 not transfer them to the Myrtißorae. 



The author concludes that the Cornaceae, for anatomical reasons, 

 should not be placed in the same cohort with the Araliaceae and 

 the Umbelliferae. E. de Fraine. 



Worsdell, W. C, On some points in the Stern Anatomy 

 of Euphorbia virosa and Aloe dichotoma. (Ann, Bolus Herb. I. 11. 

 p. 67-71. 1914.) 



The author sumraarises the result of an investigation of the 

 above stems as follows: The pith of the stem of the succulent Eu- 

 phorbia virosa, Willd. from Namaqualand, as also of other species 

 mentioned, is permeated by air cavities of very large dimensions. 

 These cavities have a lysigenous mode of origin and probably 

 serve as a special type of aerating Channels. The water-storingtissue 

 of the primary parts of the stem of Aloe dichotoma, Linn. from 

 Namaqualand is traversed by a network of intercellular Spaces 

 which are formed, in the first place schizogenously, but for the most 

 part according to the lysigenous method. In the secondary ground- 

 tissue, the air-cavities are formed schizogenously as a result of ten- 

 sions set up during the increase of girth of the stem. Thus. in the 

 Aloe-siQm. there are two distinct Systems of aerating tissue, and in 

 this plant as well as in Euphorbia virosa we see examples of a com- 

 bination, within one-and-the-same-tissue, of the two functions of 

 wa':er-storing and of airstoring. E. M. Jesson (Kew). 



Bordas, M. Seh. P., Doctrinas actuales sobre la reduc- 

 ciön numerica de los cromosomas y su aplicacion ä la 

 espermatogenesis de la Sagitta bipunctata Quoy et Gaim. 

 (Memorias R. Soc. Espanole Hist. nat. X. 1. Madrid, 1914.) 



Cette memoire, resultat des observations de l'auteur, faites sous 

 la direction du Prof. V. Gregoire de l'Universite catholique de 

 Louvain, comprend deux parts, dont la premiere (p. 5—51), 

 comme introduction, fait la description generale des ph^nomenes 

 .de la division cellulaire, la seconde (p. 52—108) indique l'etat des 

 connaissances sur la spermogenese de la Sagitta, la technique adop- 

 tee, l'exposition et discussion des faits observes, et en appendice 

 l'auteur s'occupe de la mitose somatique. La memoire est accom- 

 pagnee de gravures dans le texte et de 8 planches. 



J. Henriques. 



Dahlgren, K. V. O., Der Embryosack von Plumbagella ein 

 neuer Typus unter den Angiospermen. (Sv. Vet.-Akads 

 Ark. f. Bot. XIV. 8. 10 pp. 1915.) 



Bei allen von Verf. untersuchten Phimbaghiaceae entstehen bei 

 der Reduktionsteilung der Embryosackmutterzelle keine Zellen. 

 Bei den Staticeae teilen sich die Kerne noch einmal. Es entsteht ein 

 normaler achlkerniger Embryosack. Bei Phimbagella micrantha 

 aber findet nach den beiden meiotischen Teilungen keine weitere 

 Kernteilung statt. Die vier Makrosporenkerne konstituieren unmit- 



