530 Lewis . — The Behaviottr of the Chromosomes 
be perfect. The time of fixation was from twenty-four to thirty-six hours, 
and the material was then washed in running water twelve hours, passed 
through the grades of alcohol, chloroform, and paraffin, and embedded 
in paraffin. Sections were prepared varying in thickness from five to 
twenty microns. Bleaching was effected by placing the slides for a few 
minutes in an alcoholic solution of hydrogen peroxide. The stains used 
were the triple stain and Haidenhaine’s iron-alum haematoxylin. For the 
stage of the resting nucleus and mitotic figures the triple stain is far 
superior, but for other stages of the prophase the iron-alum seems to give 
better results. Full sets of preparations were made using both stains. 
The Phenomena of the Prophase. 
The present trend of thought regarding reduction has directed attention 
especially to the prophase of the first division, with especial emphasis upon 
the resting nucleus and the stage of synapsis. At the close of the last 
division in the archesporial cells of both Pinas and Thuja the nucleus soon 
passes over into what is universally regarded as the resting stage. The 
nuclear content consists at this time of irregular chromatic lumps con- 
nected by delicate, anastomosing linin threads which stand out with great 
clearness and beauty in sections well differentiated with the triple stain. 
Concerning the question of whether two substances are to be distinguished 
here, nothing new can be added, but there is no doubt that the staining 
reaction of the chromomeres and the so-called linin is quite distinct. There 
seems to be a tendency on the part of the chromatin to become quite finely 
dissected, but there are always some bodies which remain quite large 
(PI. XXIX, Fig. i). The number of these lumps is always quite in excess 
of the number typical of the somatic chromosomes of the sporophyte genera- 
tion and does not approximate to this number by subsequent fusions. Mottier 
(’07) has shown for Lilian that the extent of dissection in the chromatic 
masses may be quite variable in closely connected cells of the same anther- 
loculus. In this genus it seems that in some of the cells the bodies in question 
become finely broken up and separated along the linin threads, while 
in others they remain more closely intact. He has raised the question 
as to what extent this difference in appearance may be caused by the 
reagents, as it seems quite probable that the action of osmic acid might 
exert some such influence on the chromatic substances, but no very definite 
results have as yet been obtained. This writer observed and figured nuclei 
exhibiting both of these conditions as they passed on into the synaptic con- 
dition, and they seem to behave in precisely the same manner, no matter 
which condition prevails in the resting nucleus. He concludes, therefore, 
from a long comparative study of the forms investigated, that the number 
and size of the chromatic lumps is a matter of minor importance. Miyake 
(’05) made a comparative study of a long list of plants, and he finds that 
