THE HIGHER CRYFTOGAMIA. 431 



The impregnated germinal vesicle which is pressed into 

 the lower end of the corpuscuhim of Juniperus communis 

 and sabina, as well as that of Thuja orietitalis, divides by 

 a transverse septum into two daughter-cells (PI. LXV, fig. 

 10), of which the lower one frequently encloses the larger 

 portion of the protoplasm of the mother-cell. The upper 

 wall of the upper cell is usually soon dissolved (PL LXI, 

 fig. 4) ; when it lasts longer (as is often the case) the 

 same vigorous downward expansion which takes place 

 after some time in all the cells of the pro-embryo, takes 

 place also in the uppermost of the two cells of the rudi- 

 mentary pro-embryo (PI. LXV, fig. 3).* The farther 

 development of the daughter-cell of the impregnated 

 germinal vesicle resembles, in its essential features, that 

 of the Abietineae. It divides by longitudinal septa, and 

 the elongated daughter-cells divide by transverse septa, 

 which latter division is repeated in the terminal cells. The 

 number of longitudinal divisions of the second cell of the 

 pro-embryo is however far less definite than in the Abietineae. 

 The most usual number of the rows of cells of the pro- 

 embryo is four, but pro-embryos are also often found which 

 consist of only two or on account of the longitudinal di- 

 vision of one of the latter of three longitudinal rows of 

 cells (PI. LXV, fig. 4). 



These rows of cells very soon become disconnected after 

 the pro-embryo has broken through the base of the corpus- 

 culum. Their longitudinal expansion is still more re- 

 markable than in the Abietineae (PL LXV, fig. 5). If 

 after the last transverse division (PL LXV, fig. 6) of the 

 terminal cell of one of the detached rows of cells, the for- 

 mation of the embryo commences by the production of 

 differently inclined septa in the lower one of the newly- 

 formed cells, then the lower end of the last cell of the pro- 

 embryo, upon which the. embryo is seated, grows very 



* These enlarged upper portions of the impregnated germinal vesicle exhibit 

 a very large nucleus with proportionally large nucleoli. The occurrence of the 

 division of the germinal vesicle into an upper and a lower portion, of which the 

 latter is destined for more active further development, the former remaining 

 stationary, and sometimes containing a nucleus, sometimes not brings to 

 mind the similar phenomena in Gagea and Fritillaria (' Entstehung des Embryo,' 

 pp. 20, 21). 



