216 _ BOTANICAL GAZETTE [SEPTEMBER 
megaspore formation, and he proposes a different criterion. ‘A 
distinction,” he says, “between the first division of a megaspore 
and a division giving rise to megaspores is that while in the first 
case no cell plate is formed on the spindle, in the latter case either 
a wall or a cell plate is formed on the spindle.”” Brown admits 
the compound nature of the embryo sac of Liliwm and Peperomia, 
but for the reason just quoted refuses to admit it in the case of 
Cypripedium. To be consistent, he ought not to allow it for 
Lilium, since in this case a cell plate is formed in the third mitosis of 
the embryo sac. His distinction breaks down, however, in the case 
of Clintonia; in fig. 8 the first division of the megaspore nucleus 
is accompanied by a cell plate. It seems to the writer that the 
general principle of a compound embryo sac, while not altogether 
free from difficulties, furnishes the explanation of a large number 
of abnormal embryo sacs. 
McMaster UNIVERSITY 
Toronto, CANADA 
LITERATURE CITED 
This list does not include papers catalogued in CouLTER and CHAMBER- 
LAIN’S Morphology of angiosperms (1903); such papers when referred to in the 
text are indicated by the author’s name and the year of publication in paren- 
theses, as (HALL 1902). 
1. Brown, W. H., The nature of the embryo sac of Peperomia. Bor. 
Gaz. 46:445-460. 1908. 3 
2 , The embryo sac of Habenaria. Bor. Gaz. 48: 241-250. 
a. ere D. H., The embryo sac of Pandanus, Bull. Torr. ne cha 
36: 205-220. 1909. 
4. Coutter, J. M., Relation of megaspores to embryo sacs in angiosperms. 
Bor. GAZ. 45:361-366. 1908. 
5. Ernst, A., Zur Phylogenie des Embryosackes der Angiospermen. Ber. 
Deutsch. Bot. Gesells. 26a: 419-437. 1908 
6. Geerts, J. M., Beitrige zur Kenntnis der Cytologie und der partiellen 
Sterilitat von Oenothera Lamarckiana. Rec. Tray. Bot. Néerl. §:93-206. 
1909. 
7- McALuisTer, F., The development of the embryo sac of Smilacina stel- 
lata. Bor, Gaz. 48:200-215. 1900. 
8. MopiLewski, J., Zur Embryobildung von Gunnera chilensis. Ber. 
Deutsch. Bot. Gesells. 26a: 550-556. 1908 
