S°8 
The Ohio Naturalist. 
[Vol. IX, No. 7, 
interchange of the granular chromatin and the individual shape 
(probably dependent on the linin structure) still be retained. 
The chromatin granules appear to become diffused and spread 
out no less than the linin, to be massed together again at definite 
stages in the ontogeny. 
All the figures are from accurate Abbe camera lucida drawings on the 
same scale. Fig. 1. Spirem of second cleavage just at the time of the 
separation of the chromosomes. The spirem is already broken at one 
point. The position of the two long and two short chromosomes is clearly 
marked, showing that the chromosomes are not yet paired. Figs. 2-9. 
Pole views of equatorial plates of first and second cleavage. 
Then again it is even possible, with all of our present knowl¬ 
edge, that the chromatin acts as a unit organism and produces 
periodically a definite number of chromosomes of rather definite 
size and form without localizing any given quantity of the sub¬ 
stance in any definite part. There is no need to insist that a 
viscid plasm must comport itself like a set of wooden blocks as 
some would have us believe. However, I think that most of the 
evidence so far presented points to a material individuality of 
the linin groundwork of the chromosome. 
