1921] MACPHERSON—CUSCUTA AND CONVOLVULUS 307 
4. Multiple embryos in Convolvulus seem to be developed from 
the synergids. 
5. The endosperm in Cuscuta is scanty, and in both Convolvulus 
and Cuscuta is the result of free nuclear division. 
The writer wishes to thank Dr. Met. T. Coox for suggesting 
this problem, and for his interest and assistance throughout the 
course of the investigation. 
RvuTGERS COLLEGE 
New Brunswick, N.J. 
EXPLANATION OF PLATES XXV -XXVII 
PLATE XXV 
Fic. 1.—Longitudinal section of flower of Cuscuta Gronesit, showing 
position of o 
Fic. 2. Snigitadinal section of Cuscuta Gronovii, showing 2-nucleate 
stage of embryo sac. 
Fic. 3.—Four-nucleate stage of embryo sac. 
Fic. 4.—Eight-nucleate stage of embryo sac before mature organization, 
showing degenerating cells of nucellus, rendered prominent by presence of 
large number of starch 
IG. 5.—Two-celled embryo. 
Fic. 6.—Four-celled embryo with suspensor. 
Fic. 7.—Eight-celled embryo, elongated type with swollen base. 
Fic. 8.—Older embryos, same type as fig. 7. 
Fic. 9.—Embryo of more spherical type. 
Fic. to.—Advanced embryo of elongated form 
Fic. 11.—Advanced embryo of spherical form with 2-celled suspensor. 
Fic. 12.—Same type of embryo as fig. 11. 
PLATE XXVI - 
Fic. 13.—Advanced embryo of urnlike form. 
Fic. 14.—Urnlike embryo slightly older than fig. 13. 
Fic. 15.—Very advanced embryo, showing elongation not accompanied 
by ferentiation o of embryonic tissue. 
Fic. 16.—Coiled embryo as found in mature seed. 
Fic. 17. one of embryo showing two scales (a); apex of embryo showing 
structure of scale (4). 
Fic. 18.—Endosperm in Cuscuta surrounding embryo rather closely. 
Fic. 19.—Perisperm sometimes seen accompanying endosperm in Cuscua, 
