114 Anatomie. — Biologie. — Varietäten, Descendenz, etc. 



two masses, each of which fuses with the phloem of the nearest plu- 

 mular trace. The xylem comes into contact with the protoxylem of 

 the plumular Strands. The epicotyledonary bundles fuse in pairs and 

 the metaxylem becomes less abundant but no typical root struc- 

 ture obtains. 



The cotyledonary traces in Pep. amplexifolia enter the axis as 

 normal collateral structures. In each fusion takes place with the 

 nearest epicotyledonary bündle, the phloem and the metaxylem of 

 both trace and bündle Coming into contact. Lower down two large 

 bundles result and an endodermis appears. There is no definite 

 rotation of the protoxylem Clements; they seemingly become exarch 

 by the movement of the metaxylem. These changes have much in 

 common with those occurring in Arum macidatuni. 



Pep. tithymaloides and Pep. maculosa resemble Pep. amplexifolia. 

 The phloem of the seed leaf traces branches only after entering the 

 axis and there is no rotation of the protoxylem; the epicotyledonary 

 traces play a prominent part. In Hoiittiiynia cordata and Saunirus 

 cermins the transition phenomena are identical. The phloem of the 

 cotyledonary traces branches on arriving near the centre of the axis 

 and fuses with that of the epicotyledonary traces. The protoxylem 

 becomes exarch by rearrangement of the xylem Clements. 



The author concludes that Peperoniia is a reduced genus and 

 suggests that the epiphytic habit of many forms has been the deter- 

 mining factor in the reduction. He discusses the phylogenetic impor- 

 tance of the transition phenomena. M. Wilson (Glasgow). 



Reed, H. S., and 1. Smoot, The mechanism ofseed-dispersal 

 in Polvgoniim inyginianiun. (Bull. Torrey Bot. Club. XXXIII. 

 p. 377—386. July 1906). 



The achenes are provided with a long lignified style, and when 

 this is broken off the achene is projected for some distance. It is 

 found that the stalk of the achene has a „separation-laycr" stretching 

 across it; above this the vascular tissues enclose a dome-shaped mass 

 of pith, the cells of which are thin-walled and are subjected to 

 pressure as the fruit ripens. When the fruit is broken off at the 

 separation-layer the elasticity of the thinwalled pith causes the fruit 

 to be ejected. M. A. Chrysler. 



Druery, C. T., Sports and species. (Gardener's Chronicle. 

 Vol. XL. p. 296-297. 1906). 



The author points out the remarkable evidence in favour of 

 de Vries' Mutation Theory which is afforded by the Sports so often 

 met with by fern-collectors. He considers that at least 2000 such 

 definite „leaps" are on record, many of which would have given rise 

 to good specific distinctions if they had only possessed the faculty of 

 enduring in Nature. Under the conditions afforded by cultivation 

 many of these Sports are easily perpetuated from spores, and gene- 

 rally breed quite true. The author refers to a few examples of the 

 establishment of such sports in nature, usually however they are 

 only recorded as isolated individuals. R. H. Lock. 



