VOLUME XL NUMBER 2 
BOTANICAL GAZETTE 
AUGUST, 1905 
SPOROGENESIS IN PALLAVICINIA. 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY. 
LXXV. 
Tn ee eR Re Cs fe ae 
ANDREW C. Moore. 
oe lO 
(WITH PLATES III AND Iv) 
THE presence of a quadripolar spindle in the division of the 
spore mother cell of Pallavicinia deci piens was announced by FARMER 
in 1893, and in 1894 he published his detailed studies upon the same 
plant. The most remarkable feature of these papers is the significance 
which the author attributes to a quadripolar spindle as a means 
for the simultaneous distribution of the chromatin to the four daughter 
cells which become the spores. 
According to FARMER’s account (5, 6), the structure in question is 
. developed quite early, before any evidence of approaching division is 
visible in the nucleus. Later the nucleus becomes lobed, and finally 
four chromosomes make their appearance. The number is increased 
by division to eight, which point off in pairs to the four lobes of the 
Spore mother cell. “A further doubling of the chromosomes occurs, 
So that four of these bodies . . . . go to form the nucleus in each 
Spore. The whole process is very much crowded up, the four-rayed. 
spindle persisting to the end; and even after the exodus of the chromo- 
Somes, traces of it can still be seen converging to the original center.”’ 
cc, . Presence of a quadripolar spindle is of itself not surprising, 
since tripolar, quadripolar, and multipolar spindles have been fre- 
quently described by various authors; but in every case these struc- 
represent early stages in the development of the achromatic 
and later become normal bipolar spindles. The peculiar 
81 
figure 
