Nichols, A morphological study of Juniperus communis var. depressci. 215 
The division of the body cell. — The division of the 
body cell to form the male cells takes place about four days after 
the pollen tube enters the archegonium chamber, and less than 
three days before fertilization. As pointed out by Coker (1903b) 
in Taxodium , this division usually occurs almost simultaneously 
with that of the central cell of the archegonium. Ordinarily two 
male cells, equal or nearly so in volume, and bounded by definite 
membranes, are formed, as described in the European form by 
various observers. These cells are at first hemispherical and lie 
close together (figs. 58, 52, 91), but after separating they become 
approximately spherical (figs. 53, 94). A slight inequality in their 
size is sometimes noticeable, but there is no doubt that they are 
physiologically equivalent, as will be proven later. The formation 
of two functionally equivalent male cells is of uniform occurrence 
among the Cupresseae and in Sequoia. On the other hand, but 
one male cell (or nucleus) appears to be functional in the Taxeae, 
Podocarpeae , and Abieteae. It would seem, as suggested by Juel 
(1904) and Coker (1907), that the formation of two functionally 
equivalent male cells (or nuclei) is restricted to those genera in 
which one pollen tube comes in contact with, and therefore has 
the opportunity to fertilize, more than one archegonium. 
Juel (1904) describes in Cupressus Goweniana a peculiar 
condition which has occasioned considerable discussion. Here he 
finds that, in contrast to the usual conditions among the Cupresseae , 
several (as many as twenty) male cells are formed in a single 
pollen tube. Lawson (1907b) examined two other species of 
Cupressus and finds that there more than two male cells are 
never produced. He therefore regards the condition observed by 
Juel as “simply an interesting abnormality”. Juel, however, 
considers this phenomenon a reversion to a primitive type and, 
coupling it with the fact referred to above that in this group it 
is possible for a single pollen tube to fertilize several archegonia, 
he concludes that the phylogeny of the Cupresseae has been 
different from that of the other conifers. Juel’s opinion that the 
Cupresseae are descended from an ancestor in which a complex 
of male cells was formed is strengthened by the results of Cald- 
well (1907), who finds that in Microcycas such a condition actually 
exists, and that there the male gametophyte normally develops 
sixteen male cells. Moreover Noren (1907) describes the occurrence 
in the pollen tube of J. communis of a large body cell with three 
nuclei. while the writer has noted several cases in the form under 
/ 
consideration where more than two male cells have been 
formed by the division of the body cell. Fig. 54 represents 
an instance where four male cells have been thus produced. To 
be sure, such conditions are not normal, and it is probable that 
two of these cells always develop at the expense of the others, 
so that eventually only two are functional, as might be inferred 
from the conditions shown in fig. 94. But although the writer is 
not prepared to discuss the question of the probable ancestry of 
the Citpresseae, he ventures, the opinion that the unusual conditions 
