—— 
Nr Pati 
1903] CURRENT LITERATURE 235 
of the felt, the multipolar spindle, and the completion of the spindle. The 
conclusion is reached that, from the very early prophases, there is present in 
the cytoplasm a distinct fibrous system which, in conjunction with another set 
of fibers of nuclear origin, forms the spindle. The fibers of an early reticu- 
lum become arranged into a radial system ; this in large part passes into an 
extra-nuclear felt, and the fibers of the felt form the extra-nuclear portions 
of the spindle. The fibers are something more than lines of force or expres- 
sions of strains or stresses. They are organs with distinct chemical and 
physical properties which eee their power to do particular kinds of 
work. No centrosomes were observed at any stage in mitosis.— CHARLES 
J. CHAMBERLAIN, 
H. O. JuEL™ has recently studied the development of the megaspore in 
Casuarina, basing his results upon material of an undetermined species col- 
lected in Algeria in January Igo, and material of C. guadrivalvis collected 
at Naples in March of the same year. The principal results are as follows: 
Each of the numerous embryo sac mother-cells, by two successive divisions, 
Sives rise to four megaspores. The cells of the archesporium are dis- 
tinguished by their larger nuclei and ‘denser contents. The first nuclear 
division in the megaspore mother-cell is marked by the usual synapsis stage 
and by a reduction in the number of chromosomes. The number of chromo- 
somes at this divison was not determined definitely, but was not less than 
‘eight nor more than twelve, while the number in sporophytic cells was about 
twice as large. Bodies of kinoplasmic aspect appear at or beyond the poles 
of the spindle during the mitoses which give rise to the four megaspores, but 
these bodies are not regarded as centrospheres. They resemble the dense 
areas which have been described in various gymnosperms. The later stages 
were not studied, but the writer remarks that in regard to the development 
of the embryo sac, the entrance of the pollen tube and the formation of the 
embryo, he can only confirm the account of Treub.— CHARLES J. CHAMBER- 
LAIN, 
THE REINVESTIGATION of the fossil, Wil/iamsonia gigas Carr.,° was 
Suggested by Wieland’s researches upon Cycadoidea, and there seems to be 
Considerable resemblance between the two forms. 
According to the present account, the structures in Williamsonia gigas 
which have been described as “male flowers” are really the axes of ovulate 
Strobili from which the layer of ovules has become detached after maturity. 
The staminate structures were probably comparable to those described by 
*JUEL, H. O., Ein Beitrag zur oe der Samenanlage von 
Casuarina. Flora g2: 284-293. p 
SLIGNIER, O., Le fruit du Williamsonia gigas Carr. et les Bennettitales, docu- 
ments nouveaux et notes critique. Mémoires de la Société Linnéenne de Normandie 
21> 19-56. figs. 9. 1903. 
