Davis. — Nuclear Studies on Pellia. 157 
The cones of fibrillae are not spindles, and the figure pre- 
sented is very far from the metaphase of mitosis. Farmer holds 
that the arms of the quadripolar body represent the astral 
portions of incomplete spindles, but he makes it plain that 
these arms in Pellia act in pairs, so that nuclear division is 
after the normal type, with two successive mitoses in place 
of a simultaneous division of the nuclear into four, as in 
P allavicinia. It is a phenomenon of prophase, and the true 
spindle has a very different structure. 
The mitoses in the spore-mother-cell are two in number and 
successive, with a short period of rest between the first and 
second division, during which the two daughter-nuclei pass 
into a resting condition. The spindle presented at the meta- 
phase of the first mitosis is remarkable for the great breadth 
of the poles and the very large number and delicacy of the 
fibres that traverse its axis. Not infrequently one of the 
poles will be so broad that it actually forks (see Fig. 9), part 
of the fibres lying chiefly in one lobe and the remainder 
chiefly in another. In other cases the spindle will present 
the appearance shown in detail in Fig. 10 and characterized 
by the broad rounded poles. It should be noted that the 
delicate spindle fibres end in a region of protoplasm rather 
free from large granules, which is bordered by cytoplasm 
containing plastids and having a spongy structure. The 
writer’s preparations gave no hint that these poles were ever 
occupied by bodies comparable to centrospheres or centro- 
somes. On the contrary the broad, flat, rounded or concave 
poles indicated that the spindle-fibres were not influenced by 
a well-defined centre. While the spindle is not multipolar 
in the manner so clearly shown in certain Spermatophytes, 
there being no conspicuous separate bundles of fibres, never- 
theless the conditions are essentially similar. The parallel 
spindle-fibres are not gathered to a point but are distributed 
over a very broad area. 
While the daughter- nuclei are being organized, the spindle- 
fibres grow fainter at the poles, and very shortly a line of 
granules appears in the equatorial zone (see Fig. it) marking 
