
a 

1901 | THE LIFE HISTORY OF ERVTHRONIUM 375 
especially figs. g6 and 47, also compare the undivided chromo- 
some, jig. 44, with a chromosome in the daughter star, fig. 57). 
There is not a single example which will not agree with the sup- 
position of a transverse division, while many of the figures 
could not be explained on the supposition of a longitudinal one. 
And while it may perhaps be granted that a transverse division 
has not been absolutely established, it may be said that there is 
much less evidence in favor of a longitudinal one. In the next 
division the chromosomes are V-shaped and the longitudinal 
splittings perfectly apparent (figs. 69, 70). 
Although there is no way known to the writer of tracing the 
origin of the reduction chromosomes in this nucleus to two 
previous ones, theoretically one might consider it possible that 
the reduction chromosome represents two normal chromosomes, 
and the closed loop the point where the usual transverse break | 
should have taken place. Were this the case, the points of 
attachment of the spindle fibers at or near the two free ends 
would represent the heads of the two simple chromosomes, and 
the break at the head of the loop during metakinesis simply the 
delayed division bringing about the usual number of pieces. 
But such a process would necessarily result in a qualitative 
division. 
The process here described is essentially the same as that 
reported for Lilium Philadelphicum, and the interpretation is 
similar, since it appears to the writer, after a long and careful 
Study of the objects, that no other interpretation seems possible. 
On account of the contradictory character of the investiga- 
tions so far published, it appears that one or the other set of 
observations has been wrongly interpreted, or else there is more 
variation in the phenomenon of chromatin reduction than is 
generally supposed. There may not be so much uniformity in 
the manner in which reduction is brought about as our present 
ideas in regard to the nature of chromatin seem to demand; 
and once the hypothesis is accepted that the chromatin organs 
are not the only bearers of heredity, there is no reason why 
a large amount of variation should not be present. There is 
