234 Nichols, A morphological study of Juniperus communis var. depressa. 
The tapetum persists until after the formation of prothallial 
tissue. 
From four to ten archegonia are organized, and, a§ in the 
other Cupresseae, these form a single complex which is surrounded 
by a layer of jacket cells. 
Pecuiiar aster-like structures, termed asteroids, are conspicuous 
in the central cell of the archegonium and persist nntil after fer- 
tilization. Their function is obscure. 
The division of the central cell nuclens takes place about 
three days before fertilization and is approximately simnltaneons 
in all the archegonia of a group. The spindle of this division is 
apparently entirely of intra-nuclear origin. 
A true ventral canal cell is never formed. The ventral canal 
nuclens usually disintegrates, but sometimes persists for a long time, 
and may divide mitotically. 
In the mature egg nucleus the most conspicuous features are 
the nucleoli and pseudonucleoli. Some of the latter are presumably 
related in some manner to the chromatin. 
% 
Fertilization takes place in June, and an interval of a 
week may elapse between conjugation in different flowers on the 
same plant. 
Both male cells may be functional. 
The entire male cell may enter the egg, but frequently the 
cell membrane is cast off outside. 
The male nucleus and the egg nucleus apparently fuse while 
in a resting condition, and the fusion nucleus becomes surrounded 
by a mantle of starch derived from the male cell. 
No distinction between male and female chromatin is apparent 
until the Organization of the spirems of the first Segmentation di¬ 
vision, when two separate masses of chromatin may be clearly 
distinguished. 
The spindles of the first division of the fertilized egg and of 
the following divisions are intra-nuclear. 
Usually eight free nuclei are formed before the appearance 
of walls, but in exceptional cases wall development is delayed until 
after the fourth nuclear division. 
Cell divisions in the upper tier of cells of the proembryo give 
rise to the suspensors and the cells of the rosette. 
Note: Since the completion of this work there has appeared a paper by 
Miss A. M. Ottley on “The development of the gametophyte and fertilization 
in Juniperus communis and Juniperus virginiana ”. (Bot. Gazette 48: 31—46.) 
ln the main her results are in accord with those of the writer. She describes, 
however, the formation of a distinct stalk cell (p. 34), a structure which the 
investigations of the writer have failed to demonstrate. Also the fact should be 
noted that the mature male cells are spherical, not hemispherical (1. c. p. 35), 
