20 



THE LIFE-HISTORY OF A FERN 



. ofr Sporophytic budding. It is plain that such growths are only methods 

 of amplification of the morphological individual; though ultimately quite 

 separate from the parent plant, there is no reorganisation of the protoplasts 

 involved in their initiation. 



There is, however, an alternative mode of increase in number of 

 individuals, which deals with much larger numbers of potential germs, 

 and involves a mych greater complexity of the phases of production than 

 the mere sporophytic budding : it is by means of spores. Since this 

 spore-production is a constant feature in the normal life of all Ferns, and 



^~ - 





FIG. 4 . 

 Vertical section of the sorus of Nephrodinin />7/.r-;//<j.\. (After Kny.) 



indeed of Archegoniates at large, while sporophytic budding only occurs 

 in relatively few, there is good reason to believe that this was a more 

 primitive and important form of propagation. It therefore demands more 

 serious attention. 



An examination of the leaves of the Male Fern will show in many 

 cases, and especially in young plants, merely a smooth, rather pale green 

 under surface : these are then the vegetative leaves, or " trophophylls" as 

 they are sometimes called, and they always appear first in the develop- 

 ment of the individual. But other leaves of older plants, and especially 

 those formed later in the season, bear on their lower surface, and chiefly 

 near their apical part, numerous roundish patches, which are green or 

 brown according to age : these are the sori, and the leaves bearing them 



