535 
in Pirius and Thuja. 
That synapsis has to do with the rearrangement of the chromatin seems 
probable, but just what takes place is a matter of pure theory. Farmer (’07) 
suggests that there probably occurs in synapsis an organization of the 
homologous chromomeres into chromosomes ; that the homologous chromo- 
somes so derived from the maternal and paternal chromatin respectively 
then unite to form the heterotype bivalents. The conjugation of the 
somatics is conceived as being effected end to end. Each bivalent consists, 
therefore, of homologous maternal and paternal primordia. The question 
naturally arises here as to just what significance is to be attached to the 
term homologous ; for it becomes at once evident that, if the chromosomes, 
so conjugating during synapsis, are exact homologues, there is no basis for the 
transmission of paternal differences, unless we modify our conception by 
the idea of dominance. If these members of the bivalents are exact 
homologues, then the first division is equational and not differential, although 
reducing. 
The extent to which affinity of the primordia will cause them to unite 
seems to underlie all theory of chromosome formation. For certainly the 
theory of the individuality of chromosomes, the formation of differentials, 
and the conjugation of somatics during synapsis, is based on the affinity of 
the units of which they are composed. That this affinity is based on 
chemical and physical laws seems quite reasonable, but one must not lose 
sight of the fact that these activities are taking place in living protoplasm. 
Mottier (’07) suggests that during synapsis pangens of like affinity 
become united into homologous chromomeres, and that these chromomeres 
then come together to form chromosomes. This idea, carried to its ex- 
treme form, must arrive at the conclusion that certain chromosomes are 
composed always of the same primordia, for if homologous units unite 
persistently they must form bodies which represent always the same charac- 
ters, and in this sense they will be individuals. Farmer (’07) maintains that 
e the chromosome must be indifferent as to the chromomeres which enter 
into its formation \ He states, however, that at meiosis the pairing takes 
place in such a way that like joins with like to form the pseudochromo- 
somes. It becomes evident that if this condition has become fixed the 
chromosomes represent groups of homologous characters united together 
by mutual affinity. But, on the other hand, if the chromosomes are formed 
out of the chromomeres by the organizing power of the cell, as maintained 
by some writers, then a chromosome represents only an accidental accumu- 
lation of primordia and not a permanent entity. 
The behaviour of the nucleolus has been so thoroughly discussed in all 
research on the behaviour of chromatin that it would seem useless to enter 
into a further discussion of the matter here. I have not, however, been able 
to recognize such a direct relationship between the chromatin and nucleolus 
as described by Cardiff (’06) for Acer, but am disposed to agree with the view 
