PLATE XXII. 

 Pinus Strobus. 



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

 this division. X 47 2 - 



243. The two segmentation-nuclei fully formed. X47 2 



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

 sion. X 472. 



245-246^. 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. X^2. 



2500:. The same after the nuclei have begun their downward movement. 



X62. 

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



the surrounding cytoplasm. X 47 2 

 25 la. An archegonium after the nuclei have almost reached the base of the 



oosphere. X^2. 



251^. A portion of fig. 25 la, showing details in nuclear structure, and 

 fibers in the surrounding cytoplasm. X47 2 - 



(198) 



