1906] OVERTON—THECOTHEUS PELLETIERI 477 
Although attempts have recently been made to discredit HARPER’S 
results on the method of free cell formation in the ascus, no very 
convincing evidence has been brought forward to show that it is more 
like that in the sporangium. JuEL (:02) in his work on Taphridium 
seems to think that HARPER has placed too much stress on the action 
of the kinoplasmic fibers as one of the chief distinguishing character- 
istics of the process, saying: “ Vorlaiifig konnen wir nicht die Rolle 
des Kinoplasmas bei der Zellbildung zur nota characteristica der 
freien Zellbildung machen, sondern miissen diesen Begriff in der 
herrkémmlichen Weise auffassen.”” Apparently JuEL has failed 
to comprehend the essence of HARPER’s definition. 
FAULL (:05) does not believe that the methods of spore formation 
in the ascus and sporangium are so different as to prevent assumption 
of their homology. He favors the view that homologizes the ascus 
with the zoosporangium of the Oomycetes, as an argument in favor of 
the origin of the Ascomycetes from the Oomycetes. The most 
complete account of cell formation in the zoosporangia of the Oomy- 
cetes is that given for Saprolegnia and Achlya, although the behavior 
of the nuclei has not been thoroughly enough studied. 
The earliest workers in the study of spore formation were influenced 
by their a priori views on the cell theory as a whole, and NAGELI used it 
to support his doctrine that new cells are regularly formed by so-called 
free cell formation from old ones. PRINGSHEIM (’51) believed that 
spores were formed by simultaneous and not by successive biparti- 
tions of the protoplasm, being completely bounded off before the 
appearance of a cellulose wall. BiscEeN (’82) in his description of 
spore formation in the sporangium of the Phycomycetes believed that 
cleavage is due to a simultaneous formation of cell plates, which break 
down, being later formed again to separate the spores. BERTHOLD (’86) 
Studied oogonia, but assumed that the process in oogonia and spor- 
angia are alike. The peripheral layer of protoplasm which surrounds 
the central vacuole forms dense rounded masses about definite centers, 
which constantly increase in size, protruding gradually into the 
central vacuole. Finally the masses separate and round up, later 
swelling up so as to become pressed together and flattened. Finally 
these masses again round up, forming definite eggs or swarm spores. 
BERTHOLD claims that the position of the spores is predetermined by 
