
244 BOTANICAL GAZETTE [SEPTEMBER 
While Léwscuin admits that at present he is describing analogies, still he 
believes that these are too numerous and too striking to be merely accidental.— 
HARLES J. CHAMBERLAIN. 
Recent worl £ gy p —SAXTON®? has investigated one of the 
two species of Actinostrobus, an endemic Australian genus, and therefore well 
worth investigation. An outline of the results is as follows. ‘The microsporophyll 
bears three sporangia and about three months elapse between pollination and 
fertilization. The archegonia are numerous and deep-seated, “a group of 25-30 
being found abutting on the lower end of each pollen tube, which reaches about 
halfway down the prothallus,” the older cells of which are generally 2-nucleate 
or 4-nucleate. In proem ryo-formation, walls are formed when the two free 
nuclei divide, so that there is a 4-celled proembryo. The completed proembryo, 
consisting of few cells, fills the egg. Each cell of the proembryo (with perhaps 
the exception of the two “apical cells”) gives rise to a suspensor and an 
embryo-initial, being as independent in embryo-formation as are the pro- 
embryonal cells of Ephedra. The chromosome numbers are 8 and 16. 
TaKEDA® has studied in detail the anatomy of the leaf of Welwitschia and 
concludes that the evidence is all in favor of the Gnetales being gymnosperms, aS 
opposed to the view of LicNreR and Tison. Even the tracheae, the most striking 
angiospermous anatomical feature, are in a transition stage, showing incomplete 
perforations. 
Taxepa* has developed a theory of the so-called “transfusion tissue” of 
S8ymnosperms. He finds that the “orthodox” transfusion tissue always arises 


vestige of the centripetal xylem and is not to be regarded as of phylogenetic 
significance, its function being “water-storing.”—J. M. C. 
emmae in Radula.—The development of gemmae in two species of 
Radula has been studied by Miss Witutston.”” In R. flaccida, a native of tropical 
America, the gemmae occur on the dorsal margin of the leaves, and formation 
the enlargement of a single cell around which a transparent gelati- 
nous*substance is secreted. A periclinal wall divides the gemma initial into a 
further division, and an outer or mother cell 
nal wall. The next division gives a quadrant, 
ly function as apical cells with two 
quadrant do not produce apical cells. 

39 . ie . be 
RE —] W. T., Contributions to the life history of Actinostrobus pyramidalis 
pes otany 27:321-345. pis. 25-28. 1913. 
S Ps ah Some points in the anatomy of the leaf of Welwitschia mirabilis. 
Ann. Botany 27: 347-357, bl. 29. 1913. 
4r 
Taxepa, H., A theory of “ transfusion tissue.” Ann. Botany 2'73359-363- 1913+ 
“ WILLIsTon, 
Ruta, Bull. Torr. Bot. Club 39:329-339. figs. 37. 1912. 
