548 Lewis . — The Behaviour of the Chromosomes 
and others have derived their well-known theories of synapsis and reduction 
which are so directly opposed. In Anasa tristis much importance has 
been attached to the fact that in certain of the microchromosomes there 
is a considerable variation in size from those demonstrated in any other 
of their preparations (Foot and Strobell, W, Plate II, Photo 3 ). In this 
cell the other chromosomes are somewhat smaller than usual. It is pointed 
out that if these two parts of the bivalents be interpreted as having been 
derived respectively from the maternal and paternal ancestry, then ‘ it 
becomes necessary to accept the theory that not only two individuals can 
show exactly the same marked variations in the same chromosome, but 
that these two rare cases should unite, a condition which seems unlikely 
According to this argument it also becomes necessary that the eleven 
daughter bivalents of a group should be as constant as the equality in size 
of two daughter bivalents, and this is shown not to be the case in Anasa. 
These authors also point out the fact that if such differences in size be due 
to parental differences, then we should rarely find two daughter bivalents 
exactly alike, but that this equality of daughter bivalents is a con- 
spicuous fact. Briefly, then, the evidence derived from a study of the 
differential chromosomes of this form is not in harmony with the well- 
known hypothesis as it has been variously developed by different in- 
vestigators. 
By attributing the property of individuality to the finer units of which 
the chromosomes are composed, we do not by any means preclude the 
possibility that some chromosomes may from cell generation to generation 
retain to a certain extent their morphological continuity. It cannot be 
doubted that in cells in which divisions are taking place rapidly, the 
chromosomes of the preceding generation can often be almost certainly 
recognized as irregular lumps which have not become so finely dissected 
as may happen when divisions are further removed. My opinion is, 
however, that too much importance has been assigned to this phenomenon 
by recent observers, for, if the chromosomes are seen to be without that 
persistent individuality which has been attributed to them, then, the so- 
called prochromosomes are seen to lose the significance with which they 
have been regarded. 
Investigators have sought at different times to prove that it is possible 
under certain conditions to recognize the chromosomes of previous genera- 
tions in the resting nucleus of somatic and germ- mother-cells. Rabl (’85) 
believed that he could recognize traces of the chromosomes in the resting 
nucleus, and he regarded the reticulum of such nuclei as having arisen by 
the giving off of anastomosing branches by the chromosomes, thus causing 
an apparent loss of identity. At the next division, however, the chromatic 
substance flows back through predetermined paths, and occupies the same 
position as before the loss of identity. He concludes, therefore, that the 
