CELL DIVISION IN PINE SEEDLINGS: 
By EDWARD L. FULMER. 
(WITH PLATES XXIII AND XXIV) 
TuE chief purpose of the following investigation was to 
determine the origin of the achromatic spindle, especially as to 
whether it originates as a bipolar or a multipolar structure. 
Along with this the subject of centrospheres was considered and 
also such other points of interest as might be observed in con- 
nection with karyokinesis. 
The greater part of the work was done on Linus laricio Poir., 
P. silvestris L. being used for comparison. The cell structures in 
the two species were found to be so nearly identical that it was 
not considered necessary to make any distinction between them 
in presenting the results of the investigation. 
The material was obtained by sprouting the dry seeds, and 
when the embryos were from 0.5-3™ long the root tips and 
cotyledons were cut off and killed in the usual manner. The 
fixing agents used were Flemming’s stronger solution and 
chrom-acetic acid. The sections were imbedded in paraffin, 
and cut 10, 5, and 4 wthick. Various combinations of stains 
were used ; but the best results were obtained with analin-safranin 
gentian-violet, and orange G; iron-alum-hematoxylin; and 
Delafield’s hematoxylin. The sections were usually stained so 
dark when killed in Flemming’s solution that it was necessary to 
let them stand in turpentine exposed to the sunlight for some 
time in order to remove the black color which otherwise inter- 
fered greatly with the proper effect of the staining reagents. 
After this treatment the sections stained very well, and the 
details of protoplasmic structure were well differentiated. 
My thanks are due to Dr. W. A. Kellerman and Mr. J. H. 
Schaffner for valuable assistance and criticism. 
aac. Contribution fromm the botanical laboratory of Ohio State University. IV. 
1898] 239 
