
1913] YORK—DENDROPHTHORA 5 Dw 
Fic. 25.—Part of section of “mamelon,” showing disintegration of basal 
megaspore; X1I50. 
Fic. 26.—Longitudinal section of two-nucleate embryo sac; X150. 
Fic. 27.—Longitudinal section of four-nucleate sac; X15 
Fics. 28, 29.—Longitudinal sections of “mamelon,” acai one of the 
embryo sac cavities filled with starch; 100 and 26 respectively. 
Fic. 30.—Longitudinal section of flower of D. gracile, showing fusion of 
short arms of embryo sacs, resulting in formation of a single tube; ¢~ same as 
tp in fig. 20; X 150. 
Fic. 31.—Part of longitudinal section of that portion of the carpel taken 
at A in fig. 13; 150. 
1G. 32.—Longitudinal section of upper portion of embryo sac, showing 
polar nuclei, nuclei of egg apparatus, and three chromatin-like bodies (y) in 
terminal portion of sac; X 250. 
FIG. 33 aL oheiadinal section of upper portion of embryo sac showin 
chromatin-like bodies (y) and group of nuclei from which those of egg apparatus 
and polar bodies are to be derived; x2 
Fic. 34.—Longitudinal section of young embryo sac, showing pseudo- 
Seitai ts projections; X1 
Fic. 35.—Longitudinal Bea of young embryo sac which has begun to © 
grow downward, showing dividing nuclei; X 2 50. 
Fic. 36.—Detail drawing of nuclei ea and p in fig. 35; X 500. 
Fic. 37.—Nuclei at micropylar end of sister sac to the sac shown in 
fig. 35; X 500 
Fic. 38.—Dividing nuclei at micropylar end of sac from which the syner- 
gids, egg, and polar nuclei are to be derived; 500 
Fics. 39, 40.—Dividing nuclei showing LS of the nucleoli; 
X 500. 
Fic. 41.—Longitudinal section of terminal portion of embryo sac; X 500. 
Fic. 42.—Cross-sections of mature embryo sac of D. gracile; X150. 
Fic. 43.—Longitudinal section of mature neers sac, showing three 
synergids, egg, and degenerating polar nuclei; X15 
IGS. 44, 45.—Longitudinal section of pia sacs of D. gracile that 
have just begun to go downward; X 250. 
