4 BOTANICAL GAZETTE [JANUARY 
Each pollen tube applies itself to but one archegonium, and in 
fertilization only the forward and larger of the two sperm cells is 
functional. ARNOLDI (1) in his study of Cephalotaxus does not men- 
tion any difference in size between the two sperm cells. He probably 
overlooked it. In Torreya taxifolia CouLTER and LAND find that 
’ the two sperm cells are very unequal and that, as in Cephalotaxus, 
each is distinct from the other. In Torreya californica, however, 
Miss ROBERTSON (17) cannot distinguish any division of the proto- 
plasm between the two sperm nuclei. She says: “these two nuclei 
seem never to be surrounded by separate masses of cytoplasm, agree- 
ing in this respect with Pinus.’”’ She finds that the two nuclei are of 
equal size and believes that only one of them is functional. 
In Taxus baccata, according to BELAJEFF (3), STRASBURGER (19), 
and JAEGER (8),3 the very unequal sperm cells are quite distinctly 
separated, and JAEGER finds their nuclei of equal size. 
In my work on Podocarpus (4) I found that only one functional 
sperm cell was formed, one nucleus being thrust to the surface of the 
cell. In the two preparations showing this stage, this nucleus did 
not seem to have any separate protoplasm of its own, but I would 
not be sure of this without further investigation. 
We find then, in summarizing our present knowledge, that all the 
Taxaceae so far investigated show but one functional sperm cell, and 
that in the Taxeae proper (with the exception of Torreya californica) 
there are two distinct sperm cells of unequal size, the difference 
being more pronounced in Taxus and Torreya than in Cephalotaxus. 
In Pinus (Miss FERGUSON, 7), Picea (MIYAKE, 12), and Abies 
(Miyake, 13), the two sperm nuclei lie in a common protoplasm, but 
the forward one is the larger and alone is functional. According to 
MorRRILL’s (14) account one would suppose that in Tsuga the two 
sperm cells are distinct, but the nucleus of the forward functional 
cell is decidedly larger, as in the other Abieteae above mentioned. 
It would seem, therefore, that in all gymnosperms whose pollen 
tubes fertilize but a single archegonium there is but one functional 
sperm cell (Taxaceae) or sperm nucleus (Abieteae).4 
3 JAEGER’S fig. 34 shows a distinct line between the two cells, but he says: “ Die 
isse der kleinen Lagonda Zelle, die von Archegonium abgekahrrt ist, Kern 
wir nur undeutlich, sie ist nicht so stark gefiarbt, wie die grosse generative Zelle. 
4 The peculiar eaiaediaria of the number of sperm eells found in conserva- 
tory grown material of Cupressus Goveniana by JuEL (Flora 93:56-62. pl. 3. 1904) 
is probably abnormal. 
