1903] BRIEFER ARTICLES 385 
with Farmer’s studies on the same form, but the two observers differ 
widely in their interpretation of the facts. Davis considers Farmer’s 
“quadripolar spindle” as a transitory stage of prophase, which should 
not be regarded as a part of the true spindle that is formed later. The 
nuclear divisions in the spore mother-cell of Pellia are effected by two 
successive mitoses, each with a bipolar spindle and the gametophytic 
number of chromosomes (eight) at the nuclear plate of each metaphase. 
There is also a well-defined period between the two mitoses when the 
nuclei are in the resting condition. The events of sporogenesis for 
Pellia are then essentially the same as those throughout, the pterido- 
phytes and in the development of pollen. 
The striking peculiarities of Farmer’s account of Pallavicinia lie 
not so much in the presence of a four-rayed achromatic figure as in 
the reported division of four primary chromosomes into sixteen, and 
their distribution to form simultaneously four daughter nuclei through 
the “quadripolar spindle.” It is necessary to emphasize this point, since 
Farmer* in a criticism of Davis’s paper on Pellia does not consider 
this matter, while taking exception to Davis’s use of the term spindle. 
Davis found a four-rayed figure during prophase in Pellia, but was not 
willing to call it a spindle, since the actual distribution of the chromatin 
takes place in the usual manner ata later period through two successive 
mitoses, whose spindles are bipolar. The four-rayed structure in Pellia 
seems to Davis a character of prophase, determined largely by the 
peculiar crowded condition of the nucleus in the center of a four-lobed 
cell. 
However, Farmer’s very positive assertion of the persistence of 
the four-poled spindle, and his detailed account of the peculiar 
arrangement of the chromosomes and their simultaneous passage to the 
four poles in Pallavicinia, makes his position a strong one to assail 
except upon a reexamination of the conditions in Pallavicinia itself. 
I am now at work on Padlavicinia Lyellii S. F. Gray, which is 
abundant in this locality. My studies are by no means complete, but 
have been carried far enough to justify conclusions on the chief events 
of sporogenesis, which are presented in this note. I have had the 
Opportunity during past summers at Woods Hole of examining Dr. 
Davis’s preparations of Pellia and have had the benefit of his sugges- 
tions and criticisms on technique. 
In preparing for mitosis the nucleus of the spore mother-cell 
‘FARMER, The —— spindle in the spore mother-cell of Pellia epiphylla. 
Ann. sapiens 15:431. 19 
