Recent Work oh the Reduction Division in Plants . 13 
Another group of observers ( e.g . Miss Sargant 1 ) have held the 
view that there is a. double longitudinal fission of the originally single 
spireme. The appearance of parallel threads in the tangle emerging 
from synapsis, interpreted by Allen and others as the approximation 
in parallel of pairs of somatic chromosomes, and by Farmer as the 
folding together into a narrow loop of two somatic chromosomes 
united at one end, is by this school of observers regarded as the 
first longitudinal split in an originally single thread. A second split 
appearing in each half of the double thread, is interpreted as a 
precocious longitudinal fission, which will be completed in the 
homotype division. 
The observers who take this view give us their facts but do not 
offer any suggestion as to how they are to be harmonised with what 
we know of the laws of inheritance. They are probably wise in 
this, since theoretical predispositions are particularly dangerous in 
cases where the actual observation is as difficult as it is here. Both 
Strasburger and Farmer on the other hand have laid much stress 
on the satisfactory relation which their descriptions of the process 
bear to certain widely accepted views on Heredity. 2 
II.— The Maturation Divisions and Heredity. 
It seems impossible to escape from the conclusion that it is the 
nuclei of the egg and sperm cells which carry on hereditary traits 
from one generation to another. This is now generally assumed as 
almost axiomatic. It is founded on the fact that fusion of one male 
and one female nucleus always occurs in fertilisation, whereas the 
behaviour of the cytoplasm is highly variable. Take the case for 
instance of two plants both belonging to the Conifers. “ In Taxo- 
dium the whole male cell enters the egg; and the male cytoplasm 
forms a sheath round the fusion nucleus and takes part in the 
formation of the embryo, whereas in Sequoia the male nucleus slips 
from its cytoplasm and enters the egg naked.” 3 If the nucleus is the 
physical basis of heredity the question next arises,—is any parti¬ 
cular part of the nucleus definitely specialised for the function of 
“character-bearing”? The answer that at once suggests itself is 
that the chromosomes which reappear so definitely at each division 
are specialised for this purpose. But this is pure hypothesis. The 
care which is taken to distribute half of every chromosome to each 
1 E. Sargant. l.c. 
2 See also W. S. Sutton. “The Chromosomes in Heredity.” 
Biol. Bull., IV., 1903. 
3 A. Robertson. “Cytology and Classification.” New PhYt., 
Vol. IV., 1904. p. 138. 
