1913] PACE—APOGAMY IN ATAMOSCO 387 
from all other cells of the sac. Even the synergids are not to be 
confused with the egg, each showing its own peculiar characters 
(figs. 10, 11). It happens that more than one egg is sometimes 
organized, and apparently all these eggs in Afamosco, but no other 
cell, may function. As all the nuclei of the female gametophyte 
have the diploid number of chromosomes, it might be thought that 
any cell could develop a sporophyte, and therefore adventive 
embryos and polyembryony would be common. But no evidence 
of adventive embryos was found; and only a few sacs with two 
embryos were seen, and in every instance they were paralleled in 
other sacs by an egg in a similar position (figs. 28, 33, 34). 
If the egg be considered a diploid gamete, then this should be 
considered parthenogenesis, but we usually define a gamete as a 
cell that fuses with another before developing, and it would seem 
that it should at least be capable of so doing if it is called a gamete. 
But this egg cell lacks this gamete character; for Atamosco seems to 
show conclusively, not only that it is capable of developing without 
fertilization, but that it will not fuse with the male gamete although 
_ the two nuclei be in contact (figs. 15-24). If this inability to fuse 
shows that it is really not a gamete, then this is apogamy. It is 
certainly apdyamy if we consider it from the standpoint of the part 
taken in the process by the male nucleus. Apogamy might be 
defined as the development of a sporophyte from a diploid egg with- 
out fertilization. Vegetative apogamy would be the development 
of a sporophyte from vegetative cells of the gametophyte, while 
parthenogenesis would be reserved for the development of a sporo- 
phyte from an egg with the haploid number of chromosomes. 
In 1900 Juet (11) showed that Antennaria alpina has very few 
staminate individuals, and even these have anthers entirely sterile 
or only slightly fertile. The megaspore develops without the 
reduction division. The Alchemilla group was investigated by 
MvrRBECK (16) in r90r and by STRASBURGER (23) in 1905. In the 
apogamous species the reduction division does not take place in 
the megaspore development. In the microspore series, in some 
species, the cells develop no farther than the mother cell stage, 
others disintegrate after the first division, while still others com- 
plete the tetrad division and imperfect pollen is produced. 
