Overton—On the Root Tips of Podophyllum Peltatum. 297 
of the longitudinal split of the next division. Yon Sclrustow 
(IS) has never observed a true longitudinal splitting of the ana- 
phasic chromosomes in Vicia fab a as described by Dehome, nor 
does von Schustrow find evidence to support Miss Merriman’s 
view. Lundegard (’12c) states that the anaphasic longitudinal 
splitting is quite as distinct as in the prophases, but von Schus- 
tow interprets Lundegard’s figures as telophasic ones. I agree 
with Lundegard that his objection to using fixed material alone 
as a basis of interpretation is a valid one. I have also compared 
fixed material with that in the living condition not only in Podo¬ 
phyllum but in many other plants, and am convinced that in many 
cases the fixed material presents the same configuration of the 
nuclear structures as is seen in the living material. I can find 
no evidence from a study of either living or properly fixed ma¬ 
terial that the telophasic chromosomes undergo a regular median 
vacuolation such as would cause them to be longitudinally split. 
I hope in the future to be able to present evidence from living 
material on this point. Sharp (’13) holds that the telophasic 
median vacuolation in Vicia is only apparent and does not really 
divide the chromosomes, which observations the results of Saka- 
mura (’14) on Vicia cracca as well as my own on Podophyllum 
support, and I cannot agree with von Schustow (’13) that the 
telophasic figures of Lundegard (’10a, ’12c), Dehorne (’ll), 
Gregoire (’06), Muller (’09), Fraser and Snell (’ll), and his 
own should be interpreted as indicating a splitting of these chro¬ 
mosomes. 
The interpretation of Bonnevie (’08) that the cross sections of 
the anaphasic chromosomes at first show a tetrad structure which 
later becomes circular, the chromatic material being denser at the 
periphery while the center is solid but less dense, is the reverse 
of that described by von Schustow (’13), who observes a darker 
cylindrical region and a lighter vacuolated inner region in the 
chromosomes of Allium. In later anaphases von Schustow de¬ 
scribes the outer cylindrical region as becoming polygonal in cross 
section with the chromatin on the periphery of the chromosomes. 
Lundegard (’10a, ’12c), holds that the axis of the anaphasic 
chromosomes is vacuolate and regards this vacuolation as bringing 
about a true longitudinal splitting. Nemec (TO) also observed 
what he regards as a true anaphasic vacuolation, often axial, but 
does not describe an anaphasic splitting of the chromosomes. 
Fraser and Snell (’ll) and Miss Digby (T9) find no vacuolation 
