101 



Fig. 56. Pollengrain with one nucleus 

 after treatment with chloralhydrate. 

 X 575. 



Fig. 57. Binucleated pollengrain after 

 treatment with chloral hydrate. 

 X 575. 



PLATE XII. 



Fig. 58. Longitudinal section of young I 

 male inflorescence. X 24. The central 

 flower is a^ yet entirely enclosed in 

 the floral envelop, the floral envelops 

 of the other flowers have prematurely 

 ruptured. The number of poUensacs 

 is very variable, they are irregularly 

 arranged. 



Fig. 59. Male flower X 17, showing the 

 single stamen and the chafl:y hairs 

 surrounding the flower. 



Fig. 60, Topview of a stamen, one sees 

 the protuberances caused by the 

 poUenchambers X 36. 



Fig. 61. Crossection of very young male 

 flowers, the perianth has been formed. 

 No differentiation has yet occured 

 in the stamen. X 24. 



Fig. 62. Frontview of a young male in- 

 florescence previously deprived of its 

 scales. X 17. The scales have been 

 spirally arranged , the angle of the 

 orthostichae may be judged oflf by the 

 two holes drawn. These holes indicate 

 the place where the stalks have been 

 attached. The floral primordia had 

 not yet formed an envelop. The dots 

 indicate the tops of the hairs. 



PLATE XIII. 



Fig. 63. Crossection of a stamen with a 



central pollensac. X 36. 

 Fig. 64. Crossection of the wall of a 



peripheral pollensac. X 250. 

 Fig. 65. PoUengrains yet attached X 600. 

 Fig. 66. Crossection ot a stamen with 



no central pollensac. X 26. 

 Fig. 67. Onenucleated pollengrain. 



X 850. 



Pig. 68, 69, 70. Sections of binucleated 



poUengrains, fig. 68 X 600, others 



X 850. 

 Fig. 71. Section of a pollensac showing 



pollenraothercells. X 250. 

 Fig. 72. Binucleated pollengrain after 



treatment with chloralhydrate. X 850. 

 Fig. 73, 74, 75. Three nucleated pol- 



lengrains, same treatment. X 850. 



PLATE XIV. 



Fig. 76, 77, 78, 79. PoUengrains with 

 three degenerating nuclei after 

 treatment with chloralhydrate. X 850. 



Fig. 80. Section of pollensac with tapetal 

 cells and with freeswiraming, pollen- 

 mother cells forming poUengrains. 

 X250. 



