1914] MANEVAL—MAGNOLIACEAE 31 
Fic. 16.—Longitudinal section of part of anther; microspore mother 
cells in oe X 300. 
17.—Transverse section of anther; tapetum and sporogenous tissue 
bifferentiatel: X 350. ’ 
18.—Transverse section of anther; tetrads of microspores; > 300. 
Fic. 19.—Section of pollen grain with reduced number of chromosomes; 
Fic. 20.—Uninucleate pollen grain; 350. 
Fic. 21.—Binucleate pollen grain; 350. 
Fic. 22.—Longitudinal section of ovule with archesporial cell; 300. 
Fic. 23. Pipe ero section of ovule through megaspore mother cell 
and tapetal cell; > 500. 
Fic. 24. A onpieadionl section of ovule; megaspore mother cell; integu- 
ments; 300 
IG. 25.—First division of megaspore mother cell; 350. 
Fic. 26.—Megaspore mother cell fol ia X 350. 
Fic. 27.—Tetrad of megaspores; 35 
Fic. 28.—Longitudinal section ‘hich ee embryo sac; X 350. 
Fic. 29.—Longitudinal section through tetranucleate embryo sac; 350. 
Fic. 30.—Longitudinal section through mature embryo sac; 350. 
Fic. 31.—Micropylar end of embryo sac; pollen tube; two-celled endo- 
sperm; X 600. 
Fic. 32.—Longitudinal eget of micropylar end of embryo sac showing 
early condition of endos 
Fic. 33.—Section of Souci hans X 500. 
Fic. 34.—Section of eight-celled embryo; X 500. 
Fic. 35.—Longitudinal section through an older aber » & 500. 
Fic. 36.—Longitudinal section of embryo and suspensor; X 300. 
Fic. 37.—Longitudinal section of embryo from mature seed; X 50. 
Fic. 38.—Transverse section of petiole; X 50. 
Fic. 39.—Transverse section of portion of a fibrovascular bundle of a 
petiole; sk 300 
IG. nies section of portion of peduncle; X 50. 
