830 The American Naturaüist. [September, 
descriptions, and finally set out to see for himself what such an 
amount of variation meant. 
Confining himself to the structure of the flowers, as he after- 
ward studied the order atthe Kew Gardens, he found some seven 
or eight modifications of its structure, arranged in two series, 
and presenting a complete gradation of forms, from the completely 
open, stellate condition, through the bell-shaped to the extreme 
tubular forms with which we are best acquainted in our American 
flora. A comparison: of these various forms indicates their deri- 
_vation by successive slight modifications from an original, simple 
flower that Professor Huxley calls the “ ur-gentian,” and Müller, 
in the * Alpenblumen,” " does not hesitate to employ to its full 
extent the Darwinian theory to explain the evolution of the 
more highly developed and differently colored forms to the 
agency of insects, particularly bees and butterflies. 
If this is admitted, it becomes quite as necessary to know the 
whereabouts and habits of bees and butterflies as to study the 
gentians themselves, and the interesting hint is thrown out that 
those gentians that have remarkably long, tubular corollas are 
found in such regions as Madagascar and Guiana, with their large 
Lepidoptera provided with a long suctorial apparatus. 
Evidently a somewhat complicated set of relations has been 
introduced ; and after still other suggestions looking in the same 
direction, Prof. Huxley adds to our feeling that the subject 1s 
growing in magnitude by saying: “I think there is no greater 
mistake than to suppose that distribution, or indeed any other 
large biological question, can be studied to good purpose by those 
who lack either the opportunity or inclination to go through 
what they are pleased to term the drudgery of exhaustive ana- 
tomical, embryological, and physiological preparation." 
Finally he raises the significant question: “Is anybody in 4 
position to deny that, in the absence of all other phenogamous _ 
vegetation, the gentians might have occupied every region an 
station on the earth’s surface in which flowering plants can exist? : 
ribution . 
h they 
Is there any ground for seeking the causes of this dist 
elsewhere than in the competition with other plants whic 
1 Quoted by Huxley, l.c. 
tak 
