Overton—On the Root Tips of Podophyllum Peltatum. 313 
scribes the alveoli as increasing in number and dimensions and as 
becoming distributed irregularly in the chromosomes, much as I 
have described them. He also maintains that nothing leads to 
the conclusion that there is a longitudinal splitting of the chromo¬ 
somes by a process of alveolation. There is, therefore, no ana- 
phasic or telophasic splitting of the chromosomes, as held by some 
authors. 
De Litardiere describes the walls of the alveoli of the anaphasic 
and telophasic chromosomes as of unequal thickness with certain 
thin and thick spots, which might be interpreted as granules, but 
he denies the existence of granules massed in a linin substratum. 
These statements are not in accord with my observations that in 
Podophyllum evidence exists that the chromosomes are made up 
of two substances, linin and chromatin, and that the latter often 
appears in the form of granules. I see no reason to change my 
view in the light of de Litardiere’s description. 
De Litardiere describes anastomoses between the chromosomes 
while at the poles, which he believes are formed as pseudopod-like 
projections from neighboring chromosomes, much as described by 
Boveri. He holds that these anastomoses are not stretched ad¬ 
hesions formed at a time the chromosomes are in contact. These 
results are at variance with my observations, as I have never ob¬ 
served anastomoses formed by any method at any stage in well 
fixed material. 
In my preliminary report on Podophyllum (Overton, ’09&), I 
stated that the telophasic chromosomes appear united into a con¬ 
tinuous spirem, but in the present paper I have shown that no con¬ 
tinuous spirem is ever present at any time in this plant. De 
Litardiere finds no telophasic spirem. 
De Litardiere also finds the extremities of some of the chromo¬ 
somes terminating at or on the nuclear membrane, much as I have 
described, often forming marked projections, a fact which I have 
cited as indicating the individual character of the chromosomes 
in this plant. The appearance of zigzag bands is also described 
in interphasic nuclei. His suggestion that, by observing cross 
sections of chromosome bands, I have been led to conclude that 
the chromosomes are formed by a condensation process is not well 
taken. My conception of the condensation process is fully dis¬ 
cussed in the main body of this paper. 
Although Mottier and I have found sixteen diploid chromo¬ 
somes in Podophyllum peltatum , de Litardiere finds only twelve 
