PLATE XXII. 



Pinus Strobus. 



Fig. 242. One aspect presented by the karyokinetic figure in the telophase of 

 this division. X 472- 



243. The two segmentation-nuclei fully formed. X472. 



244. One of the two segmentation-nuclei in an early prophase of divi- 

 sion. X 472. 



245-2463. Later stages in the second division, showing two chromatic 

 spiremes. X472. 



247. A still later stage. The two groups of chromosomes can still be made 

 out. X472. 



248. An entire archegonium showing the position of the two segmenta- 

 tion-nuclei during division. The receptive vacuole has been distorted 

 by the entrance of the contents of the pollen-tube. X 62. 



249. An archegonium showing the original position of the four segmenta- 

 tion-nuclei. X62. 



250<7. The same after the nuclei have begun their downward movement. 



X62. 

 250^. A nucleus from 250a showing details of its structure and fibers in 



the surrounding cytoplasm. X 472. 

 251a. An archegonium after the nuclei have almost reached the base of the 



oosphere. X62. 

 2513. A portion of fig. 251^, showing details in nuclear structure, and 



fibers in the surrounding cytoplasm. X472. 



(198) 



