182 Cytologie u. Befruchtung. — Morphologie u. Teratologie. 



OPPERMAN, Marie, A contribution to the Life History of 

 Aster. (Botanical Gazette. Vol. XXXVII. 1904. p. 353— 362. 

 Plates 14—15.) 

 The writer has made a comparative study of the embryo- 

 sacs of Aster undulatus, A. multiflorus, A. Novae-Belgii and 

 A. Novae- An gliae. In all these species the embryosac arises 

 from the lowest of a row of four megaspores. The mature 

 embryosac varies in shape and size, not only in the different 

 species but in different ovules of the same species. The anti- 

 podal cells are numerous and they occasionally continue to 

 grow after fertilization. In Aster Novae- Angliae and A. undu- 

 latus the lowest antipodal cells often become much enlarged. 

 In one instance in A. undulatus, an embryosac was observed 

 with two eggs and two endosperm nuclei, the extra egg being 

 close to the antipodal region. A sperm nucleus was fusing 

 with the antipodal egg and perhaps the micropylar egg had 

 already been fertilized. Charles J. Chamberlain (Chicago). 



Smith, Isabel, The nutrition of the Egg in Zamia. (Con- 

 tributions from the Hüll Botanical Labor atory. 

 LVI. (Botanical Gazette. Vol. XXXVII. 1904. p. 346—352, 

 with 6 figures.) 



The form studied was Zamia floridana. During the earlier 

 stages in the growth of the egg, no jacket is apparent. As the 

 central cell approaches its mature size and begins to fill with 

 nutritive substances, the jacket becomes conspicuous. It consists 

 of a single layer of cells rieh in protoplasm but almost destitute 

 of starch, contrasting sharply with the abutting cells which 

 are filled with large starch grains. Through the large pores 

 in the inner walls of the jacket cells haustoria-like processes 

 protrude from the egg into the jacket cells where the ends 

 of the haustoria enlarge. The knob-like ends of the haustoria 

 act as glands, discharging nutrition materials into the egg. 

 Tangential sections of such knobs may have been mistaken 

 for nuclei by previous observers. 



Charles J. Chamberlain (Chicago). 



Gagnepain, F., Contribution ä 1 ' e t u d e du p o 1 1 e n des 

 Ge'raniace'es. (Bull. Soc. Hist. nat. d'Autun. 1903. T. XVI. 

 p. 83.) 



Les grains de pollen des Ge'raniace'es sont gros (40 ä 90 (.i), 

 le plus souvent ovo'fdes avec 2 — 3 plis irreguliers. Leur couleur 

 est variable suivant les especes. L'exine est toujours papilleuse, 

 les papilles sont peu saillantes et disposees en polygones plus 

 ou moins etroits. Dans plusieurs cas l'exine renferme une 

 huile essentielle. Les grains de pollen presentent toujours trois 

 pores peu apparents sur le sec, mais tres visibles dans la 

 Glyc/3; ces pores sont larges et fermes par le corps calleux. 



