110 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
5. The spindles are of intranuclear origin, but the centrosomes 
and asters with which they are typically associated are of extranu- 
clear origin. The wall of the nucleus usually persists until a late 
anaphase stage, though exceptionally as in Neotiella albocincta it 
disappears before the equatorial-plate stage is passed. 
6. The chromosomes vary for different species from four to 
eight in number. In Neotiella they are comparatively large and 
U-shaped. 
7. Directly following the last mitosis in the ascus, and before the 
daughter nuclei pass into a resting condition, the spores are delimited 
and a plasma membrane is organized about them. The phenomena 
characteristic of this period are as follows: (1) an elongation of the 
spindle fibers bringing the daughter nuclei to the periphery of the 
mass of dense protoplasm in which they lie, and their centrosomes 
into close relations with the enveloping plasma membranes; (2) the 
delimitation of the spore plasm about each nucleus by the differen¬ 
tiation of a limiting layer of hyaline or finely granular protoplasm 
that begins adjacent to the centrosome and continues progressively 
until completed at the opposite pole ; (3) the formation of a nuclear 
wall, the time of the appearance of which is variable for different 
species and bears no relation to the delimitation of the spore plasm ; 
(4) the elongation of the nucleus after it has acquired a wall, result¬ 
ing in a pear or beaked form with the centrosome at the end of the 
beak; (5) the organization of a plasma membrane about the spore 
plasm and another opposed to it lining the cavity in the epiplasm. 
These are formed on the site of the limiting layer and are probably 
preceded by a cleavage in the latter. The cleavage and organiza¬ 
tion of the membranes begin at the centrosome end of the spore 
and progress continuously to the opposite pole. (6) Retraction of 
the nuclear beak then follows and the nucleus assumes its regular 
spherical shape. Occasionally the centrosome, lying outside the 
nuclear wall but close against it, may be demonstrable for a short 
time after this re-formation. Very rarely, as in Hydnobolites, the 
astral rays persist up to this stage. 
8. There is no evidence in the species studied that the astral rays 
fuse to form a membrane which cuts out the spore plasm and becomes 
the plasma membrane of the spore. They appear never to fuse, as 
is stated by Harper to be the case in Erisyphe and Lachnea, and the 
plasma membranes about the spores have quite a different origin. 
