Overton—-On the Root Tips of Podophyllum Peltatum. 301 
chromosomes, are of especial interest. In these plants the chro¬ 
mosomes undergo only a partial or incomplete vacuolation, the 
portions not being used to form the anastomoses remainning as 
rather large distinct chromatic masses. These masses undergo 
very little change, their substance appearing to be more concen¬ 
trated and the anastomoses between them less distinct than in 
the forms studied by Gregoire. During the prophases the anas¬ 
tomoses slowly disappear and the thicker masses enter into the 
definite chromosomes. 
Haecker (’04) observed in the epidermal cells of Siredon lar¬ 
vae that the chromosomes of the telophases become alveolized from 
without inward, so that he was able to distinguish a peripheral 
“grosswabigen Alveolenmantel” and an axillary <( gehornelt er- 
scheinenden Chromatinstrang” which later becomes further al¬ 
veolate. 
The transformation of the chromosomes by means of a grad¬ 
ual alveolation into alveolar-reticulate bands or elementary reti¬ 
cula, as described by Gregoire (’06) and others, has already been 
discussed. Sharp (’13) holds that the true alveolation of the 
telophasic chromosomes begins about the time they begin to sep¬ 
arate from one another, while von Schustow (’13) thinks that the 
vacuolation occurs much later. Sharp describes not only a median 
and irregular internal, but also a peripheral, vacuolation, the in¬ 
ternal vacuoles occurring in almost every conceivable position, and 
states that some of the internal vacuoles may rupture and break 
the surface of the chromosomes, so that each chromosome finally 
becomes a ragged chromatic band joined to its neighboring bands 
by fine anastomoses. Sharp noted that in the process vacuoles 
may finally be so placed as to give the chromatic regions of the 
chromosomes a spiral aspect, while in other cases the vacuolation 
may be more or less along the median line, which may lead to the 
erroneous interpretation of a longitudinal split, as held by cer¬ 
tain authors whose work has already been mentioned. The phe¬ 
nomena of telophasic transformation as described above is also 
supported by the observations of Muller (’12) on Najas and by 
Sakamura (’14) on Vida cracca. 
Lundegard (’10&) finds that in no case can he trace a direct 
transformation of the chromosomes of the telophases to those of 
the prophases in Allium and Yicia. In Allium parts of the vac¬ 
uolated chromosomes may persist as clumps, threads, or masses, 
a condition not found in all resting nuclei. Stomps (’10, ’ll) 
