LIFE HISTORY OF PINUS 141 



statement that the sperm-cells of Pinus are furnished with a 

 cytoplasm of their own." But, as stated in 1901, I cannot 

 confirm Blackman's statement that each sperm-nucleus is sur- 

 rounded by its own cytoplasm. 



Page 78. Strasburger ('04) states that in Taxus baccata a 

 heterotypical division occurs and that four megaspores are 

 formed which correspond to the four microspores formed within 

 the microspore-mother-cell. 



Page 89. The nature and development of this tissue in 

 Taxodium, as described by Coker ('03), is essentially the same 

 as in Pinus. A preliminary note regarding the nature and 

 origin of the spongy tissue was published by the writer in 1903. 



Page 97. Coker ('03) has made a similar observation in 

 Taxodium and Lawson ('04) finds that the nucleus of the ventral 

 canal-cell in Sequoia lies free in the cytoplasm of the egg. 



Page 109. Both Wager ('04) and Williams ('04) have re- 

 cently expressed the view that the nucleolus contributes to the 

 bulk of the chromatin, either by storing or elaborating chromatin. 



Page 124. The presence of two spiremes in the prophase of 

 the second division following fertilization and the conclusions 

 reached, as a result of this research, regarding the persistence 

 of the chromosomes are of especial interest in connection with 

 the discussions, appearing since the completion of this paper, 

 by Boveri ('04), Cannon ('03), Rosenberg ('03 and '04), and 

 others on the nature and individuality of the chromosomes. 



Pages 127 and 132. Miyake ('03) has made a similar obser- 

 vation in Picea excelsa. 



Page 129. Miyake ('03) finds that in Picea all three of the 

 nuclei, which pass into the egg from the pollen-tube but are 

 not directly concerned in fertilization, may divide before they 

 disintegrate. . 



Page 136. Miyake ('03) has described conditions very simi- 

 lar in Picea and in Abies. 



Page 137. Miss Opperman's ('04) paper has been published. 



Page 137. As already stated, Coker ('02 and '03) finds this 

 to be the normal condition in Podocarpus and in Taxodium. 

 Lawson ('04) has described a similar condition in Sequoia, and 

 he finds that, normally, the nucleus of the ventral canal-cell 

 equals in size the egg-nucleus. 



