and Laboratory Methods. 162.- 



CURRENT BOTANICAL LITERATURE. 



CHARLES J. CHAMBERLAIN, University of Chicago. 



Books for Review and Separates of Papers on Botanical Subjects should be Sent to Charles J. 

 Chamberlain, University of Chicago, Chicago, 111. 



Ferguson, Margaret C. The Development of The species Studied were Pinus stro- 



the Pollen-tube and the Division of the Gen- . „ , . r> ■■ i r, 



erative Nucleus in Certain Species of Pines. ^«-^' ^- austrtaca, P. rigida, P. )no?itana 



Annals of Botany, IS: 193-223, pis. 12-14, var. uncinata, and P. resinosa. Num- 



^ ■ erous collections extending over a 



period of three years yielded a very complete series of stages. The principal 



results are about as follows : 



Pollination, in the vicinity of Ithaca, N. Y., occurs during the last week in 

 May or the first week in June, and fertilization takes place about thirteen months 

 later. The pollen tube begins to grow soon after the pollen grain reaches the 

 nucellus, and the tube nucleus at once passes into the tube. The generative 

 cell — often called antheridial cell — divides, giving rise to the stalk cell and gen- 

 erative cell sometimes before the beginning of winter. The following summer, 

 shortly before fertilization, the nucleus of the body cell divides, but two sperm 

 cells are not formed, the sperm nuclei, on the contrary, remaining surrounded 

 by a common mass of cytoplasm. A difference in the size of these two nuclei 

 early becomes apparent, and in the pollen tube the larger nucleus is in advance. 

 The nuclear reticulum, at first delicate, becomes dense, but there is no indication 

 of a special metaplasmic substance. 



In the division of the nucleus of the body cell, the spindle is extranuclear 

 and unipolar in origin and is apparently formed by a transformation of both the 

 cytoplasmic network and the nuclear reticulum. There is thus no definite kino- 

 plasmic substance in the cell, this division indicating not persistent cell-constit- 

 uents, but rather, different manifestations of the same thing. 



No individualized centrosomes — or blepharoplasts — were found in connection 

 with the formation of the sperm nuclei, but the cytoplasmic radiations which 

 accompany the division suggest that we may have here, still persisting in the cell, 

 the vestiges of such an organ as that described by Webber. c. j. c. 



„ „ J. n rr., ^ . r The initial cells of the archegonia can 



Ferguson, Margaret C. The Development of ° 



the Egg and Fertilization in Fimis strobus. be detected about two weeks before fer- 

 Annals of Botany, IS: 435-479. pls. 23-25, tilization, which, in ^/w^j-j/r^^/^i-, occurs 

 I90I. ... 



between the tenth and thirtieth of June. 



The ventral canal cell is cut off about a week before fertilization. While the 

 writer believes that there is an intimate relation between the tg^ and the jacket 

 cells surrounding it, she was not able to demonstrate the nature and origin of 

 the proteid vacuoles, but a careful examination of a large number of preparations 

 indicates that there is no passage of nuclei from the jacket cells into the ^gg, as 

 described by Arnoldi for Pimis Pence (Strobus). No direct evidence of a nuclear 

 origin of the nutritive spheres, such as was described by Ikeno for Cycas, could be 



