Inaugural Address by the President. 561 



our present life forms. His theory of development as applied to 

 the Vegetable Kingdom nvdj be thus briefly stated : — The characters 

 of plants are transmitted to their descendants. New characters 

 besides those inherited may arise in some descendants which were 

 not possessed by the parent. When these new characters are trans- 

 mitted, and are permanent, the plants possessing them become a 

 variety. Some plants have a special tendency to variation ; others 

 are remarkably constant in their characters. No explanation has 

 been given of the reason for these differences in the nature of plants 

 or of the cause of the appearance of new characters. The differ- 

 ences are at first small. Their continuance depends on external 

 causes. In course of time new characters appear, or the old become 

 intensified, and in the struggle for existence the varieties only which 

 jDOSsess the characters best fitted to resist the prejudicial influences 

 that surround them are able to maintain their ground. The less 

 fortunate varieties perish, and in this way the connecting links 

 between the common descendants of the original stock are destroyed. 

 These descendants becoming more pronounced in their characters 

 are recognized as species. The only difference between a variety 

 and a species is the amount of divergence and the constancy of the 

 characters. Further, this in a greater degree is the only difference 

 between a species and a genus. It is accordingly concluded that all 

 the forms now observed in the vegetable kingdom are due to the 

 continual accumulation of differences in the genetic evolution of 

 these plants from the one or the few simple original forms. It 

 is held that the natural system of plants is the external expression 

 of this phylogenesis, or genetic relationship, that the development 

 of a plant from the embryonal cell to the perfect individual is a 

 short and quick repetition of the genetic development of the tribe 

 to which it belongs, and that the rocks of the earth reveal, so far as 

 the record of life is preserved, the various steps by which the 

 phjdogenesis actually was accomplished. 



Mr. Carruthers proceeded to draw attention to this last aspect of 

 the subject, as that which specially affects geologists. It deserves 

 careful investigation, for if the theory of evolution be true, then 

 the fossils which have come to our knowledge represent as far as 

 they go the extinct progenitors of existing plants, and on this 

 account possess a higher interest to us than their comparative 

 anatomy or systematic position can give to them. Reference was 

 made to the imperfection of the . geological record, but it was 

 urged that it was right to compare our knowledge of it as far as 

 it goes with the theory. What, then, is the phylogeny of the 

 Vegetable Kingdom? The most rudimentary plants are either Fungi 

 or Algas. The elementary fungal forms are believed by some to 

 be the original stock of the vegetable kingdom, while others hold 

 the primitive forms were Algaa. Mr. Carruthers argues against 

 Fungi being the earliest, on the ground chiefl}^ that they fed on 

 organized substances, and stated that evolutionists must look for the 

 earliest plants among the Alg£e. What is the testimony of the rocks 

 as to the plants existing during the long early periods of the earth's 



DECADE II. — VOL. III. — NO. XII. 36 



