226 Allgemeines. — Anatomie. 



rimental plant morphology in the study of phylogeny, and points 

 out the phylogenetic importance of the study of vigorous mature 

 roots, the nodes of vigorous mature stems, and traumatic reactions. 



E. de Fraine. 



Browne, I. M. P. B., Contributions to our knowledge of 

 the Anatomy ofthe Cone and Fertile stemof Equisetitm. 

 (Ann. Bot. XXVI. 103. p. 663—70-;. PI 64— 65. 10 Textfig. July 1912.) 



The xylem Clements of the cone of Equisetum are similar in 

 the nodal and internodal regions. In the species with well developed 

 wood the node shows a ring of wood, either complete or incom- 

 plete; in the internodes the ring tends to break up into separate 

 Strands owing to the fact that meshes of parenghyma appear verti- 

 cally above the traces that have departed. Sometimes these meshes 

 arise but a little way above the traces; at other times the xylem 

 above the latter may persists for a little distance; sometimes indeed 

 a Wide sweep of xylem persist through the whole internode. In the 

 species with less xylem no ring of wood is formed at the node» 

 most of the Strands remaining narrow and separate, though usually 

 a certain number become united at or near a node. Consequently 

 the parenchymatous meshes on one or both sides of a Strand may 

 persist through the next node. The trace-bearing portion of the 

 Strand then remains narrow and no fresh mesh arises, in such a 

 narrow Strand, above the trace. This gives rise to an anatomical 

 superposition of the traces of successive whorls, while in the forms 

 with more xylem all the traces as a rule alternate with those of 

 the whorls above and below. Even when the traces are superposed 

 the sporangiophores themselves alternate, probably owing to exi- 

 gencies of Space. The extension of the parenchymatous meshes 

 upwards, downwards and laterally leads in the forms wich less 

 xylem to the forrnation of an irregulär network of Strands. 



The phylogenetic conclusions drawn are that: 1) The sporan- 

 giophore of Equisetum is a whole appendage and not a lobe; and 

 the cone is therefore probably not on the same line of descent as 

 Calamostachys or Palaeostachya ; 2) The occasional superposition of 

 traces is due to reduction and not primitive; 3) Anastomoses of 

 vascular Strands occurring at the level of the annulus seem to show 

 that this is an arrested node — a view in harmon}'^ with the ana- 

 tomy of an abnormal cone with two annuli. 



Isabel M. P. Browne (London). 



Kirsch, S., The Origin and Development of Resin Canals 

 in the Coniferae, with Special Reference to the Develop 

 ment of Thyloses and their Correlation with the Thylosal 

 Strands of the Pteridophy tes. (Proc. Trans Roy. Soc. Canada. 

 3nd Ser. V. p. 43-109. 27 fig. 1911.) 



The aüthor gives an historical resume of the work on the resin 

 canals in the Coniferae, and describes the material chiefly used by 

 him {Pinus strobus and P. banksianä). 



The medullary rays are described, and Penhallow's and 

 Essner's views are briefiy considered. An increase in the number 

 of the medullary ray elements occurs, wherever there is an abun- 

 dant supply of food, this Statement is supported by the observations 



