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VOLUME XXVIII NUMBER «1 
MOTANICAL: “€ZAZETTE 
FULY:.1899 
STUDIES ON REDUCTION IN PLANTS.: 
Gro. F. ATKINSON. 
(WITH PLATES’ I-v1). 
I, REDUCING DIVISION IN ARISA-MA TRIPHYLLUM BY RING- 
AND TETRAD- FORMATION DURING SPOROGENESIS. 
Iv connection with some studies carried on under my direc- 
tion upon the embryology of certain of the Aracez, an effort 
was made to investigate carefully the nuclear figures during the 
formation of the pollen from the mother cells of the arche- 
Sporium. In Arsema triphyllum the figures accompanying the 
heterotypic divisions are of such interest that it seems desirable 
to offer the results of the study as a contribution to our knowl- 
-edge of this subject. Especially is this so because the evolu- 
tion of the heterotypic figures is so divergent from that 
described for most of the plants heretofore studied; and in one 
‘phase coincides so plainly with certain of the types found in 
-animals ; while in another phase it departs, so far as I have yet 
-been able to determine, from any type heretofore described. 
Early in July the young leaves and the spadix of Arisema, 
which are to appear the following spring, are formed, though 
quite small. They may be found by breaking the aerial shoot 
‘from the corm and removing several enveloping fleshy bud scales 
which protect the next season’s leafy shoot. The stamens: and 
pistils appear at this time as very minute protuberances on the 
' Paper read before the Botanical es of America, at the Boston meeting, 
‘August 1898. 
