The Geographical Distribution of the Frankeniaceae considered 
in connection with their Systematic Relationships. 
By 
William L. Bray 
Chicago, 
Arbeit aus dem Laboratorium des Königl. botan. Gartens und Museums zu Berlin. 
I. 
Introduction, and preliminary discussion of the Syste- 
matic, Morphological and Anatomical features of the 
Frankeniaceae. 
Introductory. 
The numerous contributions of recent years concerning the influence 
upon plant growth of the various physical agencies, e. g. the quality of the 
soil, exposure to extremes of temperature, to scarcity of moisture, to 
intensity of light, — in short concerning the whole category of environ- 
mental conditions, — have increased the desire to discover what has been 
the history of phylogenetic groups as related to the conditions under which 
they grow. More particularly is this true in the case of those which 
occur in conditions of extreme severity as in the xerophytic, but especially 
the halo-xerophytic groups. Where a large order, as for example the 
Chenopodiaceae, has become so thoroughly identified as halophytic, occu- 
pying all of the salt-steppes of the earth, the case is of peculiar interest, 
because in the first place, of the time involved on the side of the plants to 
attain to this adaptation, and in the second place because salt-steppe regions 
are regarded as comparatively recent-geological formations, and therefore 
it is supposable that in an age not so far removed, the position and extent 
of salt-steppe deserts was necessarily very different than at present, and 
consequently the distribution of plants at that time identified with such 
lands was correspondingly different than that of the same groups or their 
progeny of today. 
