Morphologie und Teratologie. 59, 



Johnson, D. S., On the development ot certain P'ipera- 

 ceae. (Botanical Gazette. Vol. XXXIV. 1902. p. 321—340. 

 PIs. 9—10.) 



The species investigated were Piper adunca, P. medium. 

 Heckeria umbellata and H. peltata. The embryo-sac shows 

 nothing unusual in its developmejit, the seven-nucleate stage 

 being reached as in other angiosperms. There were no indi- 

 eations of a sixteen-nucleate sac as in the related Peperomia, 

 In Piper about twenty free endosperm nuclei are formed before 

 cell walls appear and there is a still further development of 

 endosperm before the first division of the fertilized egg. The 

 synergids and antipodals are very persistent. In the ripe seed 

 the embryo is globular and, in longitudinal section, consists of 

 thirty or forty cells, showing no differentiation except a slightlv 

 developed suspensor. 



In Heckeria the endosperm is cellular from the first, there 

 being no free nuclear division. As in Piper, there is a large 

 development of endosperm before the first division of the egg. 

 The embryo is small, globular and undifferentiated, unless a 

 slight projection may be a rudimentary suspensor. The flowers 

 of Piper and Heckeria are more complex than those of 

 Peperomia. In the germination of the seeds of Peperomia and 

 Heckeria, the endosperm protrudes through a rent in the seed 

 coats and continues to Surround the embryo until the root and 

 cotyledons are differentiated. Charles J. Chamberlain. 



PONS, E., Primo contributo per una rivista critica 

 delle specie italiane del genere Atriplex. (Nuovo 

 Giornale Botanico Italiano. Vol. IX. p. 33 — 58. Con 1 tavola.f 



Dans cette premiere partie l'auteur s'occupe de la morpho- 

 logie interne et externe des especes italiennes du genre Atri- 

 plex. II decrit la structure de l'epiderme avec ses stomates et- 

 ses poils, auxquels il attribue la röle de tissu protecteur et de 

 re'servoir d'eau, de l'e'corce, du collenchyme, des tissus assi- 

 milateurs et aquiferes, de {'endoderme et du cylindre central 

 avec la moelle et les faisceaux fibro-vasculaires dans leur 

 distribution, leur Constitution histologique et leur evolution. De 

 l'anatomie on peut de'duire que ce genre presente beaucoup 

 d'affinite's avec les Amarantace'es et les Phytolaccace'es, soit 

 par les cordons de collenchyme, soit par la richesse et la 

 distribution des cristaux d'oxalate de chaux, soit par l'accroisse- 

 ment diametral de la tige, du non pas ä l'activite du cambium, 

 mais ä des couches meVistematiques surnumeraires originaires 

 du pericycle. Les deux familles se distinguent des Cheno- 

 podiace'es, et en particulier de V Atriplex, parce que dans la 

 moelle elles forment des faisceaux fibro-vasculaires centraux, qui 

 ne se trouvent jamais dans les Chenopodiace'es. 



Suivent, en ce qui concerne la Morphologie externe, des 



