280 Wisconsin Academy of Sciences, Arts, and Letters. 
granules or chromomeres are composite in structure, being com¬ 
posed of still smaller elements. By means of the progressive al- 
veolation of the ground substance or linin of the chromosomes, in 
which the granules are imbedded, these granules are separated. 
Part of the linin may be dissolved or removed in this process, while 
the remainder becomes reticulate by the anastomosing of vacuoles. 
The chromatic granules of the chromosomes become simply spread 
out or distributed by this process and are supported by the linin 
reticulum. That the anaphasic chromosomes are granular reticu¬ 
late structures is shown by figures 3. The progressive alveolation 
always occurs internally. I have never observed a chromosome 
showing any appearance of erosion. 
Although I have been able to stain the chromosomes so that one 
may see through them, and even study their internal structure 
and organization, I have not been able to discover in Podophyllum 
any such internal structural changes as have been described by 
Miss Bonnevie (’08) for Ascaris and Allium. She reports a cen¬ 
tral longitudinal axis in each chromosome, which divides longi¬ 
tudinally as the chromosome halves are separated. She regards 
this central axial portion as being composed of newly formed ach¬ 
romatic substance. I have considered this point carefully, and in 
some instances have found a central more darkly staining streak 
but always in preparations which I regard as poorly fixed. The 
same may be said concerning the massing of the chromatin in a 
peripheral cylinder. When the chromosomes are not well fixed, as 
I find in some preparations fixed in sublimate solutions, a denser 
peripheral sheath may sometimes be differentiated, but I can place 
no importance upon this appearance. Under no circumstances 
have I been able to make out any quadripartite arrangement of 
granules as described by Miss Merriman (’04) for Allium. Lun- 
degard (’10a, ? 12c) considers the axial vacuolation of the an¬ 
aphasic chromosomes of Allium and Vicia as a true split, while 
Nemec (’10) places no such interpretation on the central vacuola¬ 
tion of the anaphasic chromosomes of Allium. Although Sakamura 
(’14) finds an anaphasic central vacuolation of the chromosomes of 
Vicia, he does not regard it as a longitudinal splitting of these 
chromosomes. 
I have been unable to find any evidence of a longitudinal split¬ 
ting of the chromosomes during the anaphases as described by 
Granier and Boule (’ll) in the root tips of Endymion nutans. I 
cannot agree with the conclusions of Dehorne (’ll), based on his 
