The Origin and Development of the Apothecium etc. 
399 
the form of a knotty spirem. Later a sharply defined centrosome-like 
body appears at each end of the nucleus. This is probably not intra- 
nuclear. Maire (68) and Guilliermond (45) have described an intra- 
nuclear origin for the centrosome. Harper (48) figured the central body 
on, but outside, the nuclear membrane, which becomes depressed or 
pulled in when the spindle is formed. Fraser and Welsford (38) have 
found the central body behaving in the same way as described by Harper 
— the central bodies moving apart and later the radiations from the 
poles uniting to form the spindle. In my preparations the nuclear mem- 
brane does not persist for any great length of time, but the body at the 
poles of the spindle certainly appears to be outside the membrane. Even 
by the time the chromosomes have beeome arranged in the equatorial 
plate, the nuclear membrane may have almost entirely disappeared. 
The spindle is intranuclear. The centrosome-like body is sometimes 
plainly double, as in the vegetative divisions. In Figure 75, that at the 
lower pole is very evidently made up of more than one granule. In the 
spindle shown in Figure 74, I could see but a single granule at each pole, 
and in Figure 73 there is no sharply stained body. I have found no evidence 
of a connection between the masses of chromatin und a central body such 
as Harper (52) has described in Phyttactinia. Kadiating out from each 
pole of the spindle there is a very clearly defined polar aster, the rays 
of which may be traced far out into the cytoplasm. 
The nucleole sometimes persists and stains quite deeply after the 
spindle is fully formed. In late prophases (Figs. 74, 75) the chromosomes 
are scattered about on the spindle. They are small ovoid bodies about 
twice as long as wide. Later in the metaphase stage they are aggregated 
in the center of the spindle. What I take to be an early metaphase shows 
about twelve chromosomes, which are now split longitudinally (Fig. 73). 
The first nuclear division in the ascus is preceded by a distinct synapsis 
stage (Fig. 71) which harmonizes with the conclusions of other writers that 
this is a heterotypic division separating whole chromosomes. We should 
expect therefore to find the reduced number of chromosomes in the equa- 
torial plate. Whether my conclusions as to the number in the metaphase 
stage (twelve) is exactly correct or not, it is at least evident that about 
twice as many chromosomes appear in the first division in the ascus 
as in the nuclear divisions in the vegetative liyphae. If a single nuclear 
fusion has occurred in the life history of the fungus, the reduced number 
should be the same as that found in the vegetative divisions, which is 
probably six. Since the number appearing in the first division in the 
ascus is twelve it follows that there have probably been two nuclear 
