24 METASPERMAE OF THE MINNESOTA VALLEY. 



the nutritive tissues indifferently termed endosperm, in which- 

 ever way it is produced. 



Thp production of* seeds" This is considered by the writer 

 as of less taxonomic importance than the other points which have 

 been mentioned, especially as the "seeds" are such different 

 structures in the Archispermae and Metaspermae, However, 

 the older botanists considered seeds as structures of great 

 importance and in consequence the plants which produce seeds 

 have been grouped together under the name of SpermajJhyta. 

 Linnaeus recognised this division, but gave it the name Phaner- 

 ogamia under a mistaken notion that there was an analogy 

 between two such widely diverse phenomena as poUenisation 

 and fertilisation. The confusion brought about by this mistake 

 has lasted until our own day. Later it was proposed to call 

 these plants Anthophyta, or "plants which produce flowers." 

 Those peculiar groupings of spore-bearing organs and acces- 

 sory foliar structures which are termed flowers have, from their 

 conspicuous character and high specialisation, always received 

 particular attention and thus easily arose the early classifica- 

 tion of vegetable organisms into flowering and flowerless 

 plants — the Phanerogamia and Cryptogamia of Linneaus. These 

 divisions were based, however, not upon fundamental morpho- 

 logical characters but upon accessory, and have been pretty 

 generally superseded by systems of classification which present 

 a truer perspective by emphasising the more fundamental 

 structural and developmental characters. 



The classification of Engler and Prantl. In the Natuerlichen 

 PJlanzenfamilien Engler and Prantl adopt a classification based 

 upon characters of somewhat different value from those 

 discussed above. They divide the vegetable kingdom into four 

 branches: — I. Mycetozoa, slime-moulds; II. ThaliojJ/tyta (in the 

 widest sense); III. Enibryophyta zoidiogama (plants producing 

 ciliated spermatozoids and building up sporophytic embryos); 

 IV. Embryophyta siphonogama (plants producing pollen-tubes 

 and building up sporophytic embryos). It will be seen that 

 in this grouping a much greater merging of characters is 

 permitted than in the one outlined above. In the first place, 

 by way of individual criticism, the writer is inclined to suggest 

 that the Mycetozoa are more properly classed with the animals. 

 The presence of a contractile vesicle alone, need not determine 

 animal rank among those organisms that Haeckel terms Protista; 

 but its presence coupled with the absence of chlorophyll is 

 strong argument. Volvox globator, with its coenobial growth, 



