^89.] BOTANICAL GAZETTE. 



63 



protoplast a homogeneous superficial layer, which probably 

 produces the cell-wall, can be distinguished from the inner 

 granular mass, which is almost always in motion It is in 

 accordance with the author's views to "see in these two parts 

 also, peculiar organs of the protoplast, and to suppose that 

 the one can not be formed out of the other. He elaborately 

 shows that, for the present, there are no facts proving such a 

 transition, and that this subject deserves being thoroughly 



investigated. 



At all events there is ample evidence to prove that the 

 protoplast is an elementarv organism, possessed of an hered- 

 itary organization. When cell division takes place, each 

 daughter-cell receives its several organs as such from its pa- 

 rent cell, and there are no cases on record in which these 

 organs have been independently formed from a homogene- 

 ous protoplasmic mass. 



This conception of cell-division is called by the author 

 the il panmeristic" view, in opposition to the old " neogen- 

 etic" view, which supposed that the organs of the protoplast 

 could be newly formed after the cell is divided. As far as 

 nucleus and plastids are concerned the neogenetic view has 

 already been abandoned bv most authors. 



In the second place, the progress in our knowledge of the 

 process of fecundation is amply discussed. It is shown 

 that, according to the latest discoveries, it is the union of two 

 nuclei which chiefly characterizes this process. 



In the conjugation of algae only the nuclei penetrate each 

 other. The same is the case when a properly so-called fe- 

 cundation takes place, in spermatozoa and pollen-grains the 

 nucleus only penetrating into the ovum and uniting with its 

 nucleus. 



From these facts it appears that alter fecundation in the 

 higher organized plants the germ-cell, in truth, only contains 

 a tecundated nucleus, whilst all other hereditaiVorgans of 

 its protoplast are derived only from the mother- pfant. 



The author applies these several facts and views to the 

 hypothesis of pangenesis. In explaining this we will, for 

 convenience, suppose that the pollen of one species fecun- 

 dates the ovum of another allied species, and that in this 

 manner a hybrid is formed which, as usual, in all its char- 

 actersis midway between the parent plants. Common sexual 

 reproduction is essentially the same process, and therefore 

 the conclusions to which we come in this manner are appli- 

 cable to all other cases. 



