296 Wisconsin Academy of Sciences } Arts, and Letters. 
stains from denser portions of the chromosomes, a view some¬ 
what similar to that of Lundegard. Sharp holds that in the meta¬ 
phase the chromosomes show little differentiation, while Saka- 
mnra (’14) finds chromomeres in Vida cracca. 
That the prophasic and anaphasic chromosomes of Podophyllum 
are not homogeneous but consist apparently of two stainable sub¬ 
stances has been stated above. I have expressed the opinion that 
these two substances are linin and chromatin and that the chro¬ 
matin apparently exists in these chromosomes as distinct mor¬ 
phological units or chromomeres arranged in regular rows op¬ 
posite each other in the metaphasic chromosomes and are present 
in a single row in the anaphasic chromosomes, which fact I have 
considered as fairly good evidence that the appearance of chro¬ 
momeres is not due to fixation as held by Lundegard (’12c). On 
decolorizing such chromosomes I do not find such irregularly ar¬ 
ranged spots and masses as described by Sharp (’13) for Yicia. 
Although I do not wish to make a positive assertion that chromo¬ 
meres are present in these chromosomes, nor that their appear¬ 
ance may not be due to fixation, I am inclined to the view of 
Strasburger (’07b, ’ll) that there exist in the chromosomes defi¬ 
nite morphological units the halves of which are separated during 
the separation of the daughter chromosomes. 
In my former work on the reduction divisions in Podophyllum 
I failed to find evidence of chromomeres, but Mottier (’07) figures 
such bodies and describes the nuclear reticulum as being made up 
of both chromatin and linin. Muller (’12) finds both chromatin 
and linin bodies in Najas before the chromosomes split, and, as 
stated, holds that the splitting is initiated in the linin intervals, 
the chromomeres dividing later. Alhough Sharp (T3) holds there 
is no trustworthy evidence to support the view that chromatic 
morphological units exist in Vicia, he recognizes the 11 highly sug¬ 
gestive nature of the arrangement of the chromatin in a thin 
thread and its accurate separation into two equal parts”. 
During the anaphases several authors have described a longi¬ 
tudinal splitting of the chromosomes. Gregoire (’12) discusses 
fully the metaphasic and anaphasic phenomena, especially in the 
light of Dehorne’s (’ll) interpretation, and maintains that De¬ 
home’s scheme is contrary to the generally observed facts as Gre¬ 
goire describes them. Sakamura (T4) holds that in Vicia cracca 
neither during the metaphases nor anaphases is there any evi¬ 
dence of tetrads as held by Miss Merriman (’04), nor evidence 
