82 BOTANICAL GAZETTE [AUGUST 
interest attaching to the structure described by FARMER is the reported 
distribution of the chromatin simultaneously to the four daughter 
nuclei. If his observations and his interpretation of the spindle 
are correct, Pallavicinia occupies a unique position among plants 
and animals. s 
FARMER (7) sought through a study of other liverworts to throw 
further light on this subject. He found the quadripolar spindle 
present in Aneura pinguis, A. multifida, Scapania undulata, Fossom- 
bronia, and in other types of the Jungermanniales, but in no case 
did he find it persisting and functioning, as in Pallavicinia, in the 
simultaneous distribution of the chromatin. In these forms, accord- 
ing to his interpretation, the ends of the quadripolar spindle fuse in 
pairs and the distribution of chromatin takes place in the usual 
manner through two successive mitoses. While not directly con- 
firming his results on Pallavicinia, Farmer thinks the conditions 
found in these plants strengthen his position. He regards them as 
representing transitional stages between the normal type of division 
and the very unusual type which he reports in Pallavicinia. CAMP- 
BELL (I) and other authors generally have accepted FARMER’S 
account. 
Davis (4) from an investigation of Pellia was led to question 
Farmer’s conclusions. He regards the quadripolar spindle as. 
condition of prophase, and believes that it is always followed by two 
successive mitoses after the usual manner in the spore mother cell, 
each with a normal bipolar spindle. Farmer (8) is not willing to 
exclude the four-rayed figure from the spindle apparatus or to employ _ 
the term spindle in the restricted sense of Davis; but the main fea 
tures of the discussion are not the questions as to when the achromatic 
structure becomes a spindle and as to the limitation of this term as 4_ : 
matter of usage—points upon which authors may readily disagree. 
The fundamental differences between the views of Davis and FARMER 
lie in the history of the quadripolar spindle, and the method by which 
the chromatin in the spore mother cell is distributed to the four : 
spores. FARMER positively asserts that the quadripolar spindle — 
retains its form and that the chromatin is distributed Itaneously 
to the four daughter nuclei. Davis believes that the quadripolar 
spindle is a condition of prophase which is followed by two successive 
