150 Physiologie. — Palaeontologie. 



and that this may play an important part in the Organization and 

 development of parasites. It was found that the relative acidity of 

 two plants was of no importance in the determination of their capa- 

 city to enter into parasitic relations. The distributional movement 

 of species, bringing new pairs of species under test conditions makes 

 it probable that new parasitic unions are being constantly formed. 

 The changes ensuing when a plant becomes parasitic may include 

 some striking phenomena, examples of which are given. These 

 alterations may be discontinuous, mutatory, or distinct mutations 

 and may either be connected more or less directly with obvious 

 causes, or may be useless and aberrant. Moore. 



Shull, C. A., Oxygen pressure and the germination of 

 Xanthiiun seeds. A preliminary report. (Bot. Gaz. XLVIIl. 

 p. 387-390. Nov. 1909.) 



Experiments proved that but a small amount of oxygen pres- 

 sure is necessary for germination. This is inconsistent with the rapid 

 respi^ation previously shown (Wm. Crocker, Bot. Gaz. XLII. p. 265 — 

 291. 1906.) to occur in seeds of Xanthmin. The contradiction of 

 results is explained by the facts that the seed coats are probably 

 responsible for a large amount of the respiration and that there is 

 a strong correlation between the growth of the hypocotyl and the 

 cotyledons. Much of the oxygen used by seeds which germinate 

 with seed coats intact and in high oxygen pressure is due to con- 

 sumption of oxygen b}^ the seed coats and the cotyledons, very 

 little being used by the hypocotyls. Moore. 



Be pr y , E. W. , The Epidermal Characters of Ffenelopsis 

 ramosissinia. (Bot. Gaz. L. p. 305 — 309. Tab. 1, 2. 1910.) 



The curious stomata and spined epidermis of this common 

 American Lower Cretaceous conifer are described. Berry. 



Cockerell, T. D. A., Descriptions of Tertiär y Plants. III. 

 (Amer. Journ. Sei. 4. XXIX. p. 76—78. Tab. 1, 2. 1910.) 



In continuation of former studies Myrica diversifolia Lesq., Cra- 

 taegus acerifolia Lesq., C. lesqicereuxi Ckl., and Onoclea reducta Ckl. 

 are united to form Sorbits diversifolia which is supposed to be a 

 fossil hybrid and 5. nupta is described as new. ßoth forms come 

 from the Miocene of Florissant, Colorado. Berry. 



Holden, H. S., Note on a wounded Myeloxvlon. fNew Phytologist. 

 IX. p. 253-257. 1910.) 



As so few cases have been recorded from fossil plants, of the 

 healing of wounds. the author describes a case observed by him 

 in the petiole ot MediiUosa. He illustrates the ccUs in the neigh- 

 bourhood of the injury, which have become meristematic and pro- 

 duced a typical wound cambium. M. C. Stopes. 



Seward, A. C, Fossil Plants, a text books for students 



