IN THE VEGETABLE KINGDOM. 61 



the place of free antherozoids, as the medium of 

 impregnation. 



The first of these points of difference is that which gives 

 its most obvious character to the reproductive process just 

 as among Cryptogamia the feature most obviously distin- 

 guishing the Rhizocarps is the absence of an external pro- 

 thallium, which is tantamount to the suppression of one of 

 the two germinations (prothallial and embryonic) under- 

 gone by the fern spore. This maturation of the embryo in 

 situ, of course, affects the position of the breach of con- 

 tinuity of organization, or the dissemination of the plant 

 the severance of the new generation from the old. It 

 transfers it from the place occupied in the higher Crypto- 

 gamic orders the early part of the gamomorphic stage 

 to the interval between the protomorphic and orthomorphic 

 stages ; or rather to the commencement of the latter, for 

 the embryo is already fashioned in most species before the 

 seed is shed. But in the Coniferse, besides this, which may 

 be called the great breach of continuity, there is a lesser 

 one the shedding of the pollen, which affects only the 

 male element. Here, as elsewhere, this, of course, occurs 

 prior to impregnation. 



10. REPRODUCTION IN THE ANGIOSPERMOUS PHANEROGAMIA. 



The vast majority of the plants of the present epoch be- 

 long to this group, and principally to its higher or dicotyle- 

 donous division. The reproduction is throughout by pollen 

 grains and ovules, but both, and particularly the latter, differ 

 considerably from those of the Gymnosperms. 



The carpellary leaf, instead of merely supporting the 

 ovule, is wrapped round it to form a germen, generally of 

 a more or less flask-shaped figure, with a neck or style re- 

 sulting from the rolling up of its distal portion, and termi- 



