342 
LESTER W. SHARP 
those of Strasburger (1900), Miyake (1905), and Farmer and Shove (1905). 
The first two papers treat of the maturation mitoses. Both Strasburger, 
in his figures 97-100, and Miyake, in his figures 152 and 153, suggest a 
process of alveolation in the chromosomes during the heterotypic telophase. 
Farmer and Shove give an account of both the somatic and the maturation 
mitoses. They speak of a " vesiculation " of the chromosomes in the somatic 
telophase, the chromatin becoming a ''cloud of fine granules through the 
linin band"; and describe "broad band-like areas" with the chromatin 
in a dense "granular aggregation " during the early telophase. These condi- 
tions are faintly suggested in their figures 2, 2a, 20, and 21. But in none of 
these investigations have the changes undergone by the chromatin been 
followed closely enough to afford evidence on the time of chromosome 
splitting, or on the precise manner of the transformation of the chromosomes 
into the resting reticulum and of the latter into chromosomes. 
Description 
In order to give an uninterrupted account of the history of the chromatin 
through the critical stages — the telophasic transformation of the chromo- 
somes into the resting reticulum and the subsequent condensation of the 
latter into chromosomes — the description will begin with the metaphase. 
Metaphase and anaphase. As is usually the case with long chromosomes, 
those of Tradescantia are inserted on the spindle by their middle points. 
Six of them are thus shown in figure i (a portion of the chromosome on the 
right has been cut away). Since no detailed comparison of all the chromo- 
somes of the group has been made, it is not known whether or not this mode 
of insertion is an invariable one. The free ends of the chromosomes extend 
out in various directions, but most commonly lie more or less parallel to 
the axis of the mitotic figure. As Farmer and Shove also observe, the 
doubleness of the chromosomes reaches its maximum distinctness at this 
time. 
Because of their mode of attachment to the spindle, the chromosomes 
take the form of V's as they move toward the poles at anaphase (figs. 2, 3). 
The mottled appearance shown by the chromosomes appears to be due very 
largely to their uneven contour, though unequal density of the chromatin 
in various portions of the chromosome may be partly responsible. Nothing 
which can be called internal granules or chromomeres has been distinguished 
at this stage, and only occasionally do any vacuoles make their appearance 
so early. As they reach the poles the chromosomes become much shortened 
and thickened, and contract into two dense groups in which the limits of 
the chromosomes can be made out only with considerable difficulty. The 
new cell plate now begins to be differentiated on the fibers between the two 
groups. 
Telophase. After remaining in close contact for a short time the chromo- 
somes begin to separate from one another, and as they do so they cohere 
