822 The Amerwan Naturalıst. [September, 
But there was still needed some great fundamental conception 
to bind these facts together into a consistent whole; and this con- 
ception, brought out three years later in the famous papers of 
Wallace and Darwin before the Linnaan Society, was embodied 
and applied, more and more completely, in the various monographs 
and essays of the three botanists: Asa Gray in the United 
| States, and J. D. Hooker and George Bentham in England. 
The history of the subject now becomes so largely identical 
with the contributions of these three men? that we can do no 
better than to follow each one of them step by step in his work, 
and see, as far as we are able, the facts as they saw and interpreted 
them. 
The botanical contributions of Asa Gray, taken as a whole for 
fifty years, bore more or less directly upon the subject of geogra- 
phical distribution. One of his earliest reviews is a notice of 
Siebold’s Flora Japanica,’ in the course of which the remark is 
made that “the flora of Japan presents such striking analogies to 
that of the temperate part of North America as to render this 
work of more than ordinary interest to American botanists;” and 
again, in 1846, he takes the occasion offered in another review to 
say : “ It is interesting to remark how many of our characteristic 
genera are represented in Japan, not to speak of striking analogous 
forms.” 
This remarkable fact, having once been clearly formulated, was 
never lost sight of, and although it seemed incapable of explana- 
tion upon any theory then held regarding the nature of species, 
_ Dr. Gray lived long enough to find the clue to its meaning, and 
to show the far-reaching and fundamental nature of the principle 
involved. 
5 All mention of such works as those of Schoua and Griesbach, however valuable for 
their statement of facts, has purposely been omitted. The service rendered by those who 
collect data exhaustively and accurately is by no means called in question, but it does 
not fall within the purpose of the present sketch to consider any treatises, however a 
tended, that cannot be shown to have definitely contributed to a better comprehension 
i / ii 
omit any discussion of the well-known papers of Forbes and Darwin, although meto ihe 
was called by Hooker “ the reformer,” and the latter “the greatest lawgiver, d 
ince of seodrarthical distribution. 
5 Am. Jour. Sci., Oct., 1840. 
