18 METASPERMAE OF THE MINNESOTA VALLEY. 
such as those of Pfeiffer (27), Steudel (28) and Kuntze (29) 
together with the laws of zoological and botanical congresses 
and papers by distinguished taxonomists, such as Agassiz and 
A. Gray, have been freely consulted and the basis of nomencla- 
ture in the case of the Metaspermae has been derived from 
such critical, historical and bibliographic labors. Those 
who are interested in the detail may find abundant discussion 
in these cited works, which, together with the controversial 
and argumentative material published from time to time by the 
Royal Botanical Gardens at Kew, the Continental and Austra- 
lasian Gardens and the various botanical periodicals and 
ephemera that concern themselves with such subjects, will be 
found to present the questions outlined above, from a wide 
variety of view-points. With Kuntze, it may well be said that 
while nomenclature itself is hardly to be named a science, it is 
certainly an important adjunct of science and as such demands 
thoightful attention. 
Arrangement of families and genera. The arrangement of 
families and genera follows as exactly as possible the lines laid 
down in Engler and Prantl’s Natuerlichen Phanzenfamilien, which 
is beyond compare the most important taxonomic summary yet 
published for the plant-kingdom. This arrangement is not 
particularly different from that which has come to be generally 
recognised within the last ten years. It is similar in general 
outline to that of Luerssen (30), Drude (31) and Warming 
(314), and is a clear expression of modern views of the inter 
relationship and evolution of the flowering-plants. Such an 
arrangement is preferable to the more ancient ones just in such 
degree as it is more accurate. The accuracy of the arrange- 
ment adopted is acknowledgedly incomplete, but it is believed 
to represent the full research of the times. 
Natural divisions of the vegetable kingdom. The constant 
effort of the botanist is to make his classification of plants indi- 
cate not only resemblance but relationships. Indeed resem- 
blances are considered of value in taxonomy only in so far as they 
indicate relationships. For this reason no classification is, or 
can be stable, since no classification is ever mature or com- 
plete. The ever-progressing knowledge of plant-anatomy, dis- 
tribution, physiology and especially of embryology renders the 
(27), Pfeiffer: Nomenciator Botanicus (1874): 
(28), Steudel: Nomenclator Botanicus, ed. IL, (1840-41.) 
(29). Kuntze: Rev. Gen. (1891.) 
(30). Luerssen: Systematischen Botan. (1878-1882). 
(31). Drude: Syst. und Geogr. Anordn. Phan. (1890). 
(31%), Warming: Syst. Botan., Germ. Tran. (1890). 
