REPRODUCTION. 



203 



FIG. 126. 

 Adiantum capillus-veneris. (After Sachs.) 



well as those already referred to, will assist in further elucidating 



these relations. 



A fern-prothallmm with 



a young sporophytic fern- 

 plant is shown in Fig. 126. 



This young plant is the result 



of the fertilization of the 



archegonium. The root is 



seen at t0, the first leaf at b. 



We will now compare vascular cryptogams and phanerogams 



(Fig. 127, 1 and 2). The ruled rectangle represents the period of 



separation from the mother- plant and winter-rest ; S represents the 



asexually produced ma- 

 crospore and the embryo- 

 sac; E is the egg-cell. 

 $ Represents the micro- 

 spore in 1 and the pollen- 

 grain in 2. 



The beginner will be 

 surprised to learn that 

 the entire phanerogamic 

 plant with its flowers rep- 

 resents the asexual genera- 

 tion. If this be so, where 

 is the sexual generation ? 

 Its existence is limited to 

 a minimum of space and 

 time. In its behavior it 

 is markedly different from 

 the corresponding genera- 

 tion in the vascular cryp- 

 togams. Let us consider 

 that which is analogous 

 and that which is not an- 

 alogous. The embryo- 

 sac and the pollen -grain 

 are indeed represented by 

 analogous structures in 



the vascular cryptogams; such analogies are the most marked 



