78 COMPARATIVE EMBRYOLOGY OF THE RUBIACEAE 
real and considerable, all the cases studied are alike in the absence 
of a nucleolus, in the indistinctness of the nuclear membrane, which 
appears as if surrounded by an ill-defined zone of fine kinoplasmic 
fibers running in various directions, and in the loss, at least so far 
as direct observation can take us, of the individuality of the grand- 
daughter chromosomes, even when, as in Crucianella, the second 
splitting takes place in early telophase. 
The occurrence of a more or less complete resting stage at the 
end of the first division is a phenomenon of wide occurrence among 
the phanerogams. Authors are not agreed, however, as to the 
degree into which the daughter nuclei enter at this stage. More 
recently Schniewind-Thies has found a considerable amount of 
variations in a number of forms studied comparatively by her. It 
appears, therefore, that we may explain this disagreement on the 
ground of the occurrence of a considerable degree of variation in 
this regard. 
It does not appear to be necessary to be concerned about the 
loss of individuality by the chromosomes under the circumstances 
at least so far as the question of reduction is involved. A second 
longitudinal splitting being demonstrated to occur before this takes 
place, we are compelled to believe in the absence of positive evi- 
dence to the contrary that the rehabilitation of the chromosomes 
is complete. The Weissmannian interpretation once shut out, it 
remains for us to explain the variable degree into which the grand- 
daughter nuclei enter the resting condition apart from it. I cannot 
agree with Davis, nor do I find for him any justification in the 
literature of the subject, either on the zoological or botanical side 
of the question, when he remarks “ This conception * is intimately 
concerned with, and necessarily a part of, the recent studies 
of Guignard and Strasburger on the double longitudinal splitting 
of the chromosomes.” (L €, po 150%) 
Indeed Strasburger ae has recently shown that in Ascle- 
pias (l. c.) a complete resting stage, with a nucleolus, is formed 
between the first and second pollen divisions, without making any 
remark further than to call attention to the fact. 
* That the chromosomes maintain their edidi d in the OR nuclei after 
the first mitosis of the pollen mother-cell. 
