1 76 Davis. — Nuclear Studies on Pellia . 
activities reported by Hof (’ 98 ) and Nemec (’ 99 ) in root-tips. 
The first sign of approaching division is the elongation of the 
nucleus and development of the spirem-thread. Kinoplasmic 
accumulations then appear, forming two caps over the ends 
of the nucleus, and these organize two sets of fibrillae which 
grow into the nuclear cavity carrying the chromosomes to the 
nuclear plate. Certain arrangements of the cytoplasm some- 
times suggest asters, for the nucleus is swung in the centre 
of the cell by strands of protoplasm, but such appearances are 
deceptive. The poles of the spindles are entirely free from 
radiations or bodies comparable to centrosomes. 
There are eight chromosomes in the gametophyte and 
sixteen in the sporophyte. 
The most interesting results of these studies are perhaps 
the evidences of the various morphological manifestations of 
kinoplasm possible in the same life-history. The granular 
kinoplasm organizes (i) independently-acting fibrillae in the 
spore-mother-cell, after the manner in Pteridophytes and 
Spermatophytes, (2) a centrosphere and aster in the germi- 
nating spore which (3) give place to caps in older periods 
of the gametophyte, and (4) caps are developed in the tissue 
of the seta similar to those in root-tips. It is probable, of 
course, that there is likewise a blepharoplast at the time of 
spermatogenesis. 
University of Chicago, 
June , 1900. 
Literature Cited. 
Atkinson, s 99 : Studies on Reduction in Plants. Bot. Gaz., xxviii, 1. 
Belajeff, ’97 : Einige Streitfragen in den Untersuchungen iiber die Karyokinese. 
Ber. deut. bot. Gesell., xv, 345. 
’98 : Ueber die Reductionstheilung des Pflanzenkerns. Ber. deut. bot. 
Gesell., xvi, 27. 
Blackman, V. H., ’98 : The Cytological Features of Fertilization and Related 
Phenomena in Pinus silvestris. Phil. Trans. Roy. Soc., cxc, 395. 
Calkins/97: Chromatin Reduction and Tetrad-formation in Pteridophytes. Bull. 
Torrey. Bot. Club, xxiv, 101. 
