40 BOTANICAL GAZETTE [JANUARY 
aborted, showing at maturity a number of normal spores and a single enlarged 
microspore. X95. 
Fic. 26.—More complete abortion of microspores, with four enlarged. X95: 
Fic. 27.—Same more highly magnified. 
PLATE VI 
Fic. 28.—Microsporangium showing a few remaining but abortive tetrads, 
and only one (much enlarged) microspore. X95. 
FIG. 29.—Same more highly magnified. 
Fics. 30, 31.—Sectional views showing internal and external transitions from 
the ordinary spherical microspore, which has a central nucleus and no vacuola- 
tion, toward the megaspore form and condition; jig. 30 shows an enlarged, 
spherical, but vacuolated spore, with spheroidal nucleus laterally placed; fig. 32, 
a more enlarged, spheroidal spore, more vacuolated, with meniscoid nucleus 
apically placed. 180. 
Fic. 32.—Section of sporocarp showing primary (p) and secondary (Ss) 
megaspores, as determined by age, position, size, and stage of wall formation. 
x 
Fic. 33.—Same showing three primary (pf) and two secondary (s) mega-_ 
spores, and one megasporangium, m, containing microspores. X33. 
Fic. 34.—Same, showing one central and one lateral section of primary 
megaspores, p, and six secondary megaspores, s. X33. 
Fic. 35.—Same showing two primary (f) and two secondary (s) meebo 
and one primary megasporangium, m, containing normal and aborting micro- 
spores. X33. 
Fic. 36.—Primary and secondary megaspores more highly magnified; the 
secondary megasporangium showing three sets of tetrads in which one of the 
spores in each set has enlarged and become vacuolated (not marked in the figure), 
thus competing sharply with the functioning megaspore, s, for supremacy. 87- 
Fic. 37.—Primary megasporangium, m, containing microspores nearly mature, 
one of the oldest microsporangia, 0, containing a young secondary megaspore, 
the same age as that ere in fig. 36; the microspores are the same age as the 
primary megaspore in fig. X87. 
Fics. 38-43. sohaes in size and shape between the primary (p) and the 
secondary (s) megaspores at maturity. «44 
“Fics. 44, 45.—Enlarged megaspores sacked full of starch grains, but having 
no perinium. * 44. 
