Jolivette—Spore Formation. 
1183 
terpreted as having some such general appearance as Faull (13) 
ascribes to bis limiting layer. Such stages as Faull shows in his 
figure 21 (PL 8) in my preparations showed an inter astral 
zone. In a slightly later stage, when the fibres have increased 
in length and just before they begin to bend downward toward 
the nucleus, the interastral zone is still more pronounced, and 
this later stage Faull (13) probably took for his limiting layer. 
Faulks misinterpretation of the stages when the interastral zone 
is present may also account for the large number of prepara¬ 
tions that he found showing what he calls the limiting layer. 
Sands (37) in her paper on nuclear structure and spore-for¬ 
mation in Microsphaeri alni points out that Fault’s figures (figs. 
27, 28, 29, 34 and 35 pi. 8) of the young completely delimited 
spore with a beaked nucleus and an aster whose rays end in the 
plasma membrane may have been drawn from polar views of the 
spore. This possibility with the facts described above indicate' 
that Faulks contention that the astral rays have nothing to do 
with the delimitation of the spores is not in accord with the 
facts shown by his own preparations. 
In his study of Peziza Stevensoniana Harper (23) observed 
that at the close of the third division of the nucleus of the as- 
cus each of the eight nuclei was surrounded by a rounded plasma 
mass, which is densest near the nucleus and gradually becomes 
less dense as the distance from the nucleus increases. This con¬ 
dition is represented in his Figure 23. There can he little 
doubt both from the description and figure that this is the stage 
where the asters are in contact and that the hounding zones sep¬ 
arating the masses about the eight nuclei are the interastral zones 
described above. The asci of Peziza Stevensoniana are not 
favorable for the differentiation of the asters at this stage. 
There can he no question from the figures described above for 
Geoglossum that the rays actually bend in toward the nucleus 
just before they form, the spore membrane. There is a com¬ 
paratively long period after the third division when the polar 
rays run out radially from the central bodies and meet in the 
interastral zone after the central spindles have entirely disap¬ 
peared (figs. 5, 6, 7, 8, 9 and TO). The nuclei have become re- 
