156 BOTANY 



far-reaching are the modifications which it produces ; and thus inter- 

 mediate forms between two organs may be produced which correspond 

 more or less closely to one or the other of them. Finally, through the 

 capability of a fully-differentiated tissue to renew, as a secondary meri- 

 stem, its embryonic condition, an organ of an entirely different mor- 

 phological value may be produced instead of one already in process of 

 formation ; in this way, for example, a shoot may take the place of a 

 spore capsule. Consequently neither the abnormal interchangeability, 

 at times manifested between morphologically different members, nor 

 the development of intermediate forms between them, can be con- 

 sidered as proof of their phylogenetic connection. Malformations 



ARE, ACCORDINGLY, NOT TO BE ACCEPTED AS EVIDENCE IN MORPHO- 

 LOGICAL QUESTIONS, EXCEPT IN THE RARE CASES WHEN THEY MAY BE 

 CONSIDERED AS A REAPPEARANCE 01" ANCESTRAL QUALITIES. 



