602 Wisconsin Academy of Sciences, Arts, and Letters. 
the 'preceding telophase, (Jf) of the constant recurrence of 
chromosomes of a characteristic size and shape, (5) of the per¬ 
sistence of chromatic centers of the same number as the chromo¬ 
somes, and (6) of the independence of the paternal and mater¬ 
nal chromosomes following fertilization. 
Harper (39) has pointed out that the doctrine of the per¬ 
manency of the chromosome does not necessarily imply that the 
chromosomes themselves are composed of differentiated struc¬ 
tures as a cell is, nor that they are elementary independent or¬ 
ganisms as Boveri has conceived them to be. The chromosome 
is to be regarded as a structure “undergoing continually its own 
series of cyclic changes in resting stage, mitosis, fusion, etc. 
doubtless susceptible to minor alterations due to 
changing environment.” 
The individuality of the chromosome is questioned by some 
who regard the chromo-mere as the persistent unit. Ifottier 
(64, 65) is of the opinion that the chromosome does not main¬ 
tain complete individuality from one cell generation to the 
other. He believes “that in synapsis or earlier the pangens of 
like affinity, or those bearing like characters are brought to¬ 
gether in chromomeres. These chromomeres are then organ¬ 
ized into chromosomes. Each chromosome is accordingly com¬ 
posed chiefly of homologous chromomeres which become ar¬ 
ranged end to end, and which split to form paired chromo¬ 
somes.” He is further of the opinion that these chromosomes 
are distributed according to the rules of chance or according to 
the affinity which they have one for the other. 
Farmer (25) regards the chromomeres as “the discrete units 
which are responsible for the production of hereditary charac¬ 
ters,” and therefore the nuclear element which persists from 
one cell generation to the next. He believes that the relatively 
small number of chromosomes in cells offers a fatal objection 
to the view r that they are the primordia of the characters of the 
adult organism and therefore he has selected the chromomere 
as the structural unit. He cites an example from Darbyshire, 
who says that in pure races of Pisum sativum and Fisum ar- 
rense there are at least 18 pairs of characters which behave in 
