FAULT: DEVELOPMENT OF ASCUS. 
91 
to fade out. As soon as the centrosome begins its retreat, the rays 
begin to spread out in all directions. 
Whether these rays are precisely the ones that were found 
extending out from the centrosomes in the spindle stage cannot be 
affirmed with absolute certainty. But there seems no reason to 
think that they are any other, nor that they do not include practi¬ 
cally all of those rays. This being the case, there is corroborative 
evidence that the layer of protoplasm that first delimited the spore 
does not consist of fused astral rays. 
Neotiella albocijntcta (B. & C.) Sacc. 
Harper’s (’ 99 ) description of spore formation in Lachnea scut- 
ellcita is the most detailed account we have of the cytology of the 
ascus in the Discomycetes. He begins with the uninucleate condi¬ 
tion just prior to the first mitosis, and his observations on this stage 
correspond with those already given by De Bary and Gjurasin. Pass¬ 
ing on to the last mitosis, he notes that the daughter nuclei acquire 
walls before “spore-cutting” is begun. They lie close to the wall 
of the ascus with their asters directed outward. The base of the 
nucleus next grows towards the center of the ascus and in this way 
a beak is formed. The formation of the spores takes place in the 
manner previously indicated for Erysiphe, so that in Lachnea, too, 
the spore plasm is “cut” out by a plasma membrane consisting of 
fused astral rays. He found that there was no aggregation of pro¬ 
toplasm at the time the spores were delimited. He had previously 
described (Harper, ’ 97 ) an aggregation in Pezizci vesiculosa as far 
back as the four-nucleated and four-spindle stages, but concludes 
from a re-examination that his previous observations were wrong. 
JLeotiella albocincta has proved valuable in a study of this kind 
because of the fact that its nuclei are unusually large, and its proto¬ 
plasm is free from undesirable substances. Extranuclear bodies are 
of rare occurrence. The stages in the early development of the 
ascus, too, are readily followed, but this phase of the subject will 
receive consideration later on. The material was collected in small 
quantity near Toronto, Ontario, in the latter part of October, 1902. 
Beginning with the mature uninucleated condition (pi. 9, fig. 40) 
it is noticeable that, unlike most forms, the ascus has mot vet 
attained its maximum size. There is the same differentiation of 
