492 
Katharine Foot and E. C. Strobell 
in the organism, like other morphological entities. If this is the cor- 
rect view, then it is nothing ultimate or fundamental. We must analyze 
it into terms of the processes which have made it, and in this analysis 
we shall sooner or later find nothing more or less than the whole complex 
of processes which constitute the organism. The organism makes the 
chromosomes, not the chromosomes the organism” (pag. 33). 
Our cytological studies have eaused us to sympathize with the many 
investigators "syho have expressed skepticism of the causal nature of the 
cliromosomes. For several years we have argued that the chromo- 
somes in the forms we have studied show too much variabihty, both 
in their morphological and physiological expressions, to justify those 
theories which obviously demand a rigid compliance to a definite mode 
of expression. We demonstrated in 1905 that the form and relative size 
of the chromosomes in Allololophora foetida are inconstant and in every 
publication since that date we have demonstrated variability in the 
form, relative size and behaviour of the chromosomes in every form we 
have studied, and we have consistently argued that such variability 
attacks the very foundations upon which the populär chromosome 
speculations of this decade have been built.” 
Even the few examples of variolarius and servus preparations given 
in this paper show some inconstancy in the relative size of the chromo- 
somes which can be apprcciated by a careful comparison of the photo- 
graphs. 
In photo 6 the two ordinary chromosomes at the upper left peri- 
phery of the group show a budding off of a part of their chromatin, 
which causes each to appear astonishingly like the XY chromosomes 
which are in the centre of the group. Occasionally such constricted 
portions become independent of the mother chromosomes and divide as 
individual chromosomes. 
In a recent paper on Euschistus crassus (T2 pag. 58) we described 
in some detail the occurrcnce of the Separation of such small portions of 
the chromatin from the chromosomes of the spermatocytes, and from 
the chromosomes of the embryos, and we called attention to their resem- 
blance to the supernumerary chromosomes described by Wilson (’09) 
in Metapodius, of which he says: “In behaviour they show an unmista- 
kable similarity to the idiochromosomes; and for reasons given beyond 
I believe theni to bc nothing other than additional small idiochromo- 
sonies, the presence of which has resulted from irregularities of distri- 
l)ution of the idiochromosomes in preceding generations” (p. 150). 
A similar Separation of chromatin from the mother chromosomes 
