DECEMBER 24, 1897.] 
of investigation, but it soon had many de- 
voted followers who have done much to ad- 
vance the science, among the more impor- 
tant being Zirkel, Rosenbusch, Fouqué and 
Michel Levy. 
There yet remain two illustrious names 
to be mentioned among the founders of 
geology. They are Charles Lyell and 
Charles Darwin. Lyell (1792-1875), who 
exercised a profound influence on the geol- 
ogy of his time, adopted the principles of 
Hutton, and with marvelous industry col- 
lected a vast store of facts in support of the 
doctrine that ‘ the present is the key to the 
past.’ He pushed the Huttonian doctrine 
to its logical conclusion and became the 
great leader of uniformitarianism, a creed 
which, according to the author, ‘ grew to be 
almost universal in England during his 
life, but which never made much way in the 
rest of Europe.’ Lyell’s ‘ Principles of 
Geology’ must certainly be regarded as one 
of the classics of our science. To Lyell, in 
conjunction with Deshayes, we owe the 
classification of the Tertiary into Hocene, 
Miocene and Pliocene, upon the basis of the 
proportion of living species of shells. Lyell 
was not so much an investigator as ‘a critic 
and exponent of the researches of his con- 
temporaries.’ Ramsey said of him, ‘ We 
collect the data, and Lyell teaches us to 
comprehend the meaning of them.” 
Darwin (1809-1882) did much, not only 
by his contributions to the literature of 
geology, but in the introduction of the doc- 
trine with which his name is associated, to 
revolutionize the geological thought of his 
time. His demonstration of the imperfec- 
tion of the geological record and the great 
antiquity of the earth’s crust came, accord- 
ing tothe author, ‘as a kind of surprise 
and awakening.’ 
In concluding the lectures the author 
calls attention to three prominent facts : 
first, that but three of the men considered, 
Werner, Sedgwick and Logan, could be 
called professional geologists, the others 
SCIENCE. 
933 
being either men of leisure, as Hutton, Hall, 
de Saussure, von Buch, Lyell and Darwin, 
or professionally engaged in other pursuits, 
as was the case of the great majority ; sec- 
ond, that geology affords ‘some conspicu- 
ous example of the length of time that may 
elapse before a fecund idea comes to germi- 
nate and bear fruit,’ as, for instance, the 
length of time taken for the true principles 
of stratigraphical geology to become recog- 
nized ; and third, that ‘one important les- 
son to be learnt from a review of the early 
history of geology is the absolute necessity 
of avoiding dogmatism’ the examples of 
the Wernerian catastrophist and uniformi- 
tarian schools being cited. 
In endeavoring to give a somewhat com- 
prehensive review of this latest important 
work of Sir Archibald Geikie it has been 
impossible to bring out clearly the delight- 
ful biographical and personal touches which 
so charm the reader. In the summary of 
the work which I have given it has been 
my endeavor to use, so far as possible, the 
phrases and happy expressions with which 
the book so richly abounds. The volume 
is one of much significance to the student 
of geology, as it for the first time presents 
to English readers anything like a satis- 
factory statement of the development of 
geology. Many of the men to whom we 
owe so much regarding our modern views 
of the science, and whose work has been 
but little considered by recent writers, are 
brought before us in their true proportions. 
The book must take high rank among the 
many other masterpieces of the distin- 
guished author. 
W. B. CrarxK. 
JOHNS HOPKINS UNIVERSITY. 
CHARACTERS, CONGENITAL AND ACQUIRED. 
II. 
AcquirED physical characters (properly 
so termed) may involve not only quantita- 
tive changes, which alone we have as yet 
considered, but qualitative changes also. 
