GOOD: PLANT GEOGRAPHY 761 



chanD:e, evolution rather than revolution. There have been secessions, but there 

 have also been federations, and the main outlines of the subject now are very 

 much what they were a hundred years ago. The difference is that we have a 

 deeper understanding of them. 



A second impression, or so it seems to the present writer, is that today, just 

 as in 1853, we stand on the threshold of great advances in biological thought 

 and method. Our particular subject, plant geography, involves the former 

 rather than the latter, but the indications of future change are not far to seek. 

 There is an increasing impatience with ideas which owe their perpetuation more 

 to tradition than to logic, and for many there is a growing doubt of our ability 

 to arrive at the answers of some of our most urgent problems with our present 

 major postulates. It is easy enough, one realizes, to forecast change when there 

 is no obligation to foretell its shape, but its prognostication may at least help 

 us to be ready for it and to take advantage of it. 



To this end there are two aids. The first is austerity, or perhaps asceticism 

 is a better word, in scientific thought and theory. Today the pressure of events 

 and many other influences combine to make more than ever difficult the pursuit 

 of truth for its own sake, and it must not be forgotten that this is the only real 

 road to scientific progress. There is need too for a higher standard of logical 

 argument and a stronger guard against facile generalizations and false conclu- 

 sions. The second requisite is receptiveness and suppleness of mind which, it is 

 perhaps worth stressing, is in no way antipathetic to intellectual integrity. Every 

 new idea, however fantastic it may appear at first sight, is entitled to critical 

 consideration, and the wise man will treat none with complete contempt. It has 

 been well said that all great truths begin as heresies and that all new knowledge 

 contradicts the old. However true this dictum may or may not be, it is at any 

 rate an admirable motto for the study wall of the plant geographer. 



BIBLIOGRAPHY 



Babcock, E. B. 



1947. The Genus Crepis. Pt. I. The Taxonomy, Phylogeny, Distribution, and Evolution 

 of Crepis. Univ. Calif. Publ. Bot., 21. xii + 197 pp. Berkeley and Los Angeles. 



Bentham, G., and J. D. Hooker 



1862-1883. Genera Plantarum. 1(1862-1867); 2(1873-1876); 3(1883). London: Reeve 

 and Co. 



Berry, E. W. 



1911. The Lower Cretaceous Flora of the World. In Maryland Geol. Surv., 1896 — 

 Cretaceous . . . 1911, pp. 99-151. 



Cain, S. A. 



1944. Foundations of plant geography. 556 pp. New York: Harper. 



Candolle, a. L. P. P. DE 



1855. Geographie Botanique Raisonnee. Vol. I, xxxii + 606 pp.; Vol. II, 607-1365 pp. 

 Paris: V. Masson. 



Candolle, A. P. and A. L. P. P. de 



1824-1873. Prodomus Systematis Naturalis Regni Vegetabilis. 17 vols. Paris: Treutel 

 et Wiirtz. 



