60 
Katharine Foot and E. C. Strobell 
mena whatever the details of tlieir interpretation, point to a composite 
nature of the chromosomes. 
That all chromosomes are a Segregation of smaller imits has 
frequently been claimed by cytologists — the chromomere being one of 
the many cell structures that has been figured and endowed with a 
definite function, or autocratically pronounced an artefact. Farmer ('07) 
concludes that the chromosomes are “only organized bundles of chromo- 
meres”. He says, “They might, perhaps, be compared with the hands 
that are siiccessively dealt out from a pack of cards: each new hand, 
in respect of the number of cards, may resemble, but is not really 
identical with, those of the preceding deals. So, too, the chromosomes 
which reappear at each dirision woiild be similar to, but not neces- 
sarily the same as, those of the preceding division. The material 
particles of which they are built up are shuffled in the intervals elapsing 
between one division and another”. 
It is an interesting and significant fact that recently some of the 
most ardent adherents of the theory of the individuality and continuity 
of the chromosomes have been forced to admit, largely through experi- 
mental evidence, that at some point in the chromosome cycle there is 
an interchange of materials between the chromosomes, and fiirther that 
other parts of the cell may contribute theh- share to the elaboration 
of hereditary units. When it is admitted that there is any interchange 
of materials between the chromosomes at any stage of their develop- 
ment, how is it possible logically to still ding to the hypothesis of their 
individuality and continuity? Such an amendent to the theory affords 
an opportunity for an orderly niarch of retreat from an untenable 
Position, along the same path that has been used in a somewhat similar 
retreat from like assumptions for other organs of the cell. 
New York, February 8th, 1912. 
Bibliography. 
Fick, R., '07. Vererbungsfragen, Reduktions und Cliromosomenhj'pothesen. Ergehn. 
der Anat. u. Entwicklungsgeschichte. Bd. XVI. 1906. 
Foot and Strobell. '09. The Xucleoli in the Spermatocytes and Germinal vesicles 
of Euschistus variolarius. Biol. Bull. Vol. XVI. Nr. 5. 
'10. Pseudo-Reduction in the Oögenesis of Allolobophora foetida. Archiv f. 
Zellf. Bd. V. Hft. 1. 
'11. Amitosis in the Ovary of Protenor belfragi and a Study of the Chromatin 
Nucleolus. Archiv f. Zellf. Bd. VH. Hft. 2. 
