Amitosis in tlie Ovary of Protenor belfragei and a Study ol the Chromatin Nucleolus. 221 
Zellteilung der betreffenden Art oder auch wie irgendeine andre körperliche 
Eigenschaft, z. B. wie die Tatsache, daß bei derselben Art auf der einen 
Stelle kurze, an der andern lange, oder hier pigmentierte, dort helle 
Haare wachsen oder hier Schneidezähne und dort Backzähne, hier 
immer eine kleine, dort eine Großzehe, hier ein langer Mittelfinger, dort 
ein kleiner Finger, oder eine bestimmt gestaltete Feder usw. entsteht, 
wofür wir eben ‘verschiedene Anlagen’ verantwortlich zu machen pflegen«. 
Child (1910) expresses a like conception when he says: “To speak 
specifically why should we regard the chromosome problem as fundamen- 
tally different from the problem involved in the recurrence in each genera- 
tion of five fingers upon a hand, or the regulatory development of a 
definite and characteristic number of tentacles in a piece of an actinian 
body? The farther we proceed in our physiological analysis of development 
phenomena the more evident does it become that the finger and the 
tentacle do not persist as distinct and definite entities during all the 
periods when they are not present as visible structures. The only thing 
which persists is the physiological capacity to react in a certain way 
under certain conditions, and when these conditions arise the characteristic 
structure-complex appears. 
In short, when we consider the chromosome problem from a physiolo- 
gical instead of a purely morphological point of view, and we must con- 
sider it in this way sooner or later, we can find no good reason for 
regarding it as fundamentally different from many other problems of onto- 
geny. Physiologically it is no more difficult to conceive that a piece of 
nucleus should under certain conditions give rise to the characteristic 
number of chromosomes, than that a piece of the actinian body should 
give rise to the characteristic number of tentacles. The correctness of 
the chromosome hypothesis is far from being demonstrated, and in view 
of this fact we must consider the possibility of revising the hypothesis 
to fit the facts, as well as that of bringing the facts into accord with the 
hypothesis” p. 118. 
This conception of the chromosomes as organs of the cell falls in 
line with most of the observed facts. It avoids the necessity of forced 
explanations in order to set aside the many variations which menace 
certain theories and on the other hand it in no way conflicts with the 
presence of definite forms and sizes and their frequent recurrence from 
one cell generation to the next. Furth er it avoids the objections that 
are so obvious to the assumption, that in the cases in which the accessory 
chromosome does not to divide the Spermatozoon lacking this element must 
necessarily cause the egg which it fertilizes to produce a male and the 
