FAULL: DEVELOPMENT OF ASCUS. 
93 
an account of the method of spore formation would have been 
highly desirable. 
Though on a smaller scale, the divisions of the second (pi. 9, 
fig. 44) and the third (pi. 10, fig. 49) sets of nuclei are practically 
repetitions of the first. It is noticeable with them, too, that the 
spindles may lie in any plane. The chromosomes, however, in both 
and especially in the third set are much more slender and more 
closely massed together. During the last mitosis the protoplasm 
begins to aggregate about the nuclei. 
It is towards the end of this stage that spore delimitation begins. 
The daughter chromosomes have massed together at the poles of 
the spindle, and the latter has elongated bringing the eight imma¬ 
ture nuclei near the walls of the ascus (pi. 9, fig. 45). The spindles 
may lie in any plane. Extending out from the poles in some cases 
can be detected a curved hyaline line, the beginning of the limiting 
layer similar to that described for Hydnobolites. Walls now soon 
form about the nuclei which immediately after grow in towards the 
center of the ascus, in this way acquiring a beaked shape (pi. 9, 
fig. 46). Their chromatin has passed into a reticular condition, 
though still massed in the beaked end of the nucleus. Already a 
nucleolus has made its appearance. The limiting layer of protoplasm 
advances progressively until completed at the opposite pole, and is 
considerably thicker than when first seen. At this time the spore 
plasm is distinctly differentiated. 
The succeeding stage (pi. 9, fig. 47) is characterized mainly by 
an elongation of the beaks, by some growth of both nucleus and 
spore plasmas, and a continued differentiation of the latter. The 
plasma membranes then begin to form. 
These plasma membranes as in the case of Hydnobolites are two 
in number: one covers the spore plasma and the other lines the 
epiplasm in which the spore lies. They are formed, too, on the site 
of the limiting layer. Their organization begins adjacent to the 
centrosomes, and, associated with the process of cleavage, continues 
along the limiting layer until the opposite end of the spore is reached. 
It is at this stage that surface tensions indicative of a plasma mem¬ 
brane are first apparent. In figure 48 (pi. 9) the membranes are 
but half formed, but in figure 50 (pi. 10) they are complete. The 
upper spore in figure 50 (pi. 10) shows an interesting phenomenon 
that occurs occasionally, namely, the possession of two beaked nuclei. 
