374 BOTANICAL GAZETTE [November 



Fig. 36. Same. Pollen grain; 'early spirem for division to tube and genera- 

 tive nuclei. 



Fig. 37. Same. Later stage; "cap'' showing orientation of spindle. 



Fig. 38. Same. Pollen grain showing eleven chromosomes. 



Fig. 39. Same. Telophase; wall forming. 



Fig. 40. Same. Wall completed; a chromosome omitted in the organiza- 

 tion of one of the nuclei. 



Fig. 41. Same. Pollen grain developing tube. 



Fig. 42. C parviflorum. Pollen tube within the embryo sac. 



Fig. 43. C. spectabile. About same stage as fig. 42. 



Fig. 44. Same. Earlier stage; tube within sac and one synergid below it- 



FLATE XXVI 



Iflorum. Double fertilization. 



Fig. 46. Same. Ovule with tube just entering, having passed from ovary 

 wall to micropyle. 



Fig. 47. Same. Spirems formed in all the fusing nuclei before contact. 



Fig. 48. Same. Spirems of male and female nuclei farther advanced than 

 of the nuclei to engage in the triple fusion. 



Fig. 49. Same. Pollen tube entering sac; male nuclei elongated and curved. 



Fig. 50. C. spectahile. Pollen tube unusually broad; one male nucleus some 

 distance behind the other. 



Fig. 51. C. parviflorum. Segmentation of egg; two groups of chromosomes. 



Fig. 52. C. spectahile. Segmentation of egg; two groups of chromosomes. 



Fig. 53. C. parviflorum. Male nucleus and egg just in contact; late prophase 

 of primary endosperm nucleuSj which shows thirty-three (approximately) chromo- 

 somes in three groups. 



Fig. 54. Same. Two-celled embryo; primary endosperm nucleus in late 

 prophase and showing three groups of chromosomes. 



PLATE XXVII 



three- or four-celled embryo. 



forming for division of primary endosperm 



forming. 



Same. Telophase of division of primary endosperm 



Fig. 57. Same. Endosperm of two nuclei and a two-celled embryo. 

 Fig. 58. Same. Endosperm of four nuclei. 



Fig. 59. Same. Embryo well advanced; triple-fusion nucleus still distinct 

 but in the resting stage. 



Fig. 60. Same. Older embryo; triple -fusion nucleus in spirem stage. 



Sam 



in contact. 



Same. Much 



no evidence of division. 



