298 Morphologie und Teratologie. 



lops a Short beak projection through the micropyle. Several 

 axial rows of nucellar cells degenerate to form a passage for 

 the pollen tube. E. C. Jeffrey. 



Cook, Melville Thurston, The Development of the Em- 

 bryosac in Claytonia virginica. (Ohio Naturalist. 

 Vol. ni. 1903. No. 3. p. 349—353.) 



Four megaspores and two tapetal cells are produeed from 

 the archesporium. The lowermost of of the megaspores gives 

 rise to the embryosac. Only one cotyledon develops, giving 

 the mature embryo the appearance of a Monocotyledon. 



E. C. Jeffrey. 



CouLTER, John Mrele and Chamberlain, Charles J., The Em- 

 bryogeny of Zamia. (Botanical Gazette. XXXV. iMarch 

 1903. p. 184—194.) 



The authors describe the development of the embryo in 

 Zamia floridaiia in material sent from Florida in June and 

 july, and potted for study in Chicago. Before fertilization 

 of the archegonium there is formed a ventral canal nucleus, 

 which does not become separated from the general cavity of 

 the egg by a cell wall. Subsequentiy to fertilization there are 

 256 free nuclei formed in the ^gg as the result of eight simul- 

 taneous and successive mitotic divisions. Unliice the fertilized ^gg 

 of Cycas, that of Zamia does not become centrally vacuolated 

 at the end of the phase of free nuclear division. A further 

 contrast to Cycas exists in the determination of the free nuclei 

 towards the base of the ^gg, where contrary to the course of 

 events in the genus mentioned, they are alone surrounded by 

 cell walls, the nuclei of the upper portion of the egg lying 

 naked in the protoplasma. Zamia consequently gives evidence 

 of being more specialized than Cycas and Ginkgo. The 

 authors draw an interesting comparison betvveen representative 

 Gymnosperms, in regard to the number of free nuclei formed 

 in the ^gg after fertilization. In Gingko, Zamia and Cycas, 

 there are 256 free nuclei, in Podocarpus there are 16, in Thuja 

 8, in Piniis A, and in Ephedra rarely two, while in Tiimboa, 

 Gnetiim and the Anglosperms there is no formation of free 

 nuclei at all. The two cotyledons of the embryo are free at 

 the apex, and at the base; but are more or less lused in the 

 middie. They constitute much the larger part of the embryo. 

 The plumule is large with the rudiments of several leaves. 



E. C. Jeffrey. 



MiYAKE, E., On the Development of the Sexual Organs 

 and Fertilization of Picea excelsa. (Annais of Botany. 

 XVI. March 1903. p. 351—372.) 



The material v/as gathered in the vicinity of Cornel! Uni- 

 versity. Pollination took place about the middie of May, and 



