Group SPERMAPHYTA (PHANEROGAMIA). 



IN Engler and Prantl's invaluable work, Die naturlichen Pflanzen- 

 familien, 1 we find certain innovations as regards the classification 

 of plants : conspicuous among the changes suggested are the terms 

 Embryophyta zoidiogama and Embryophyta siplwnogama, the former 

 being applied to the Bryophyta and Pteridophyta, and in the latter 

 are included the Phanerogamia. 



The researches of Hofmeister, and the more recent investigations 

 of Strasburger and others, have brought to light a multitude of 

 facts, by which we have been led to a more exact knowledge as to 

 the natural affinities between the several plant groups. Develop- 

 mental study, and our more accurate perception of the homologies 

 existing between the different families, have tended to emphasize 

 the points of contact between the various divisions of the vegetable 

 kingdom. Any system of classification is to be welcomed which 

 best enables us to give expression to recognized leading charac- 

 teristics, and at the same time to bring out in a concise phraseology 

 the differences and resemblances between class and class. Engler' s 

 new terms, if not used to supersede the older and widely known 

 designations, may at least be recognized as marking a definite 

 advance towards a better understanding of phylogenetic problems. 



In dealing with fossil plants we have constantly to face the 

 difficulties of classification. With some writers there is a tendency 

 to strain the known points of resemblance between living and 

 extinct forms, and to include both in one family or sub-class ; in 

 other cases, needless isolation may be given to fossil genera by 

 separating them from existing types. Undoubtedly the most 

 natural plan is to endeavour as far as possible to fit together the 

 representatives of Paleozoic, Mesozoic, and Cainozoi.c genera, with 

 present day plants, in a common scheme of classification. It is 

 obviously impossible in the vast majority of fossil specimens, 

 to discover anything of those characters on which a modern 



1 Teil ii. p. 2. 



