ON THE GAMETOPHYTES AND EMBRYO OF 
TAXODIUM. 
CONTRIBUTIONS FROM THE BOTANICAL LABORATORY OF THE 
JOHNS HOPKINS UNIVERSITY, No. 1 
W. C. COKER. 
(WITH PLATES I-X1) 
(Concluded from p. 27) 
FORMATION OF VENTRAL CANAL NUCLEUS. 
MourriLt (’00) has recently described in Tsuga a peculiar 
method of spindle-formation in the division of the central cell of 
the archegonium. He finds a kinoplasmic area in contact with 
the inner side of the nucleus just before its division. Fibers 
begin to grow from this area into the nucleus, pressing before 
them the nuclear wall. They gradually extend until they come 
to occupy the greater part of the nuclear cavity, and are then 
joined by similar fibers which have come in from the opposite 
pole to form the prophase of the spindle. These observations I 
cannot confirm in Taxodium. Figs. 76-90 show this division in 
detail. As already stated, fibers pass around the nucleus from 
the kinoplasmic areas or aster and merge insensibly into the 
nuclear wal]. The nuclear wall is frequently considerably drawn 
in at a point opposite the kinoplasmic body (jigs. 76, 78), but no 
strong fibers can be seen extending from one to the other at this 
point. In fact, this collapse is generally more noticeable in the 
early stages of preparatory changes. Murrill (’o1) finds such 
fibers, which he concludes have caused the depression of the 
nuclear wall. 
The arrangement between aster and nucleus at this time may 
be best compared to that between the car of a balloon and the 
bag above it, the ensheathing fibers of the nucleus terminating in 
the aster representing the ropes around the balloon connecting it 
with the car below. Fig. 76 shows the beginning of the changes 
in the nucleus which lead to the formation of the spindle. 
114 [AuGUST 
