Physiologie, — Palaeontologie. 679 



sclerification hätive du pericycle, une multiplication des fibres de 

 cette assise au niveau des faisceaux libero-ligneux de la tige, un 

 accroissement des elements vasculaires et une lignification plus ra- 

 pide de ces elements, enfin une reduction de l'ecorce par rapport 

 au cylindre central. 



La temperature realisee autour des graines pour l'etude de 

 Tinfluence des rayons X sur les graines portees & haute temperature 

 a varie entre 35° et 40°. Les graines etudiees ont ete Celles de' 

 Lupin et de Haricot. 



Les resultats obtenus dans cette seconde serie d'experiences 

 mettent en evidence l'importance que presente le facteur tempera- 

 ture dans la sensibilite des graines aux rayons X. Tandis qu'ä la 

 temperature de 15° ces rayons ne semblent avoir aucune influence 

 sur le pouvoir germinatif, ä la temperature de 35° ä 40°, et aux 

 doses employees par les auteurs, l'irradiation a toujours eu une in- 

 fluence favorisante sur la germination, L'etude de la structure des 

 plantules provenant de ces graines a confirme les resultats obtenus 

 dans la premiere partie des recherches. R. Combes. 



Bailey, I. W., A Cretaceous Pitxoxylon with Marginal Tra- 

 cheides. (Ann. Bot. XXV. p. 315—325. pl. 26. 1911.) 

 From the lignite of the Upper Cretaceous of New Yersey the 

 author describes and flgures the details of the wood of a Pityoxylon 

 showing ray tracheides. The author remarks on the identification of 

 cariferous wood in general, and on the lines of evolution in the 

 coniferae as indicated by their anatomical details, concluding by 

 proposing the name Pinus scituatensiformis for the Pityoxylon under 

 discussion. The specimen is described as being intermediate in 

 structure between the older cretaceous pines and the most primi- 

 tive living pines, and as affording additional evidence that the pri- 

 mitive pines possessed thickwalled ray parenchyma with piciform 

 lateral ray pits, and highly resinous ray parenchyma. 



Though naming a new species the author does not give a 

 diagnosis of the same. M. C. Stopes. 



Berry, E. "W., A Lower Cretaceous Species of Schisaeaceae 

 from Eastern North America. (Ann. Bot. XXV. p. 193—198. 

 pl. 12. 1911.) 

 The Baiera-like forms of leaf impressions which were described 

 by Fontaine from the American Potomac and formed the basis 

 for his genus Baieropsis have been re-examined by Dr. Berry. 

 Fontaine had made ten species of his genus. and also described 

 five species of the fern genus Acrostichopteris, which appear to have 

 insufficient foundation for their Separation. Dr. Berry retains the 

 generic name Acrostichopteris provisionally for purely vegetative 

 forms, the reproduction of which is not yet known. The forms in- 

 cluded in Baieropsis are shown to be ferns with terminal fructifi- 

 cations at the ends of the narrow leaf segments which justify their 

 inclusion in the Schisaeaceae. The name given by the author is Schi- 

 saeopsis expansa (Font.), to cover Baieropsis expansa and B. macro- 

 phylla Font. M. C. Stopes. 



Jeffrey, E. C, On the Affinities ofthe genus Yesonia. (Ann. 

 Bot. XXIV. p. 767-773. pl. 65. Oct. 1910.) 



The author describes the form and internal structure of the 



