4 
GLACIAL PERIOD. 
had derived invaluable assistance from his 
friendly advice and direction. To him I was 
indebted for an introduction to all the geolo¬ 
gists and paleontologists of Great Britain, 
with none of whom, except Lyell, had I any 
previous personal acquaintance. Through him 
I obtained not only leave to examine all the 
fossil fishes in public and private collections 
throughout England, but the unprecedented 
privilege of bringing them together for closer 
comparison in the rooms of the Geological 
Society of London. A few years later he vis¬ 
ited Switzerland, when I had the pleasure of 
showing him, in my turn, the glacial phenom¬ 
ena of my native country, to the study of which 
I was then devoting all my spare time. After 
a thorough survey of the facts I had collected, 
he became satisfied that my interpretation of 
them was likely to prove correct, and even then 
he recalled phenomena of his own country, 
which, under the new light thrown upon them 
by the glacial phenomena of Switzerland, gave 
a promise of success to my extraordinary ven¬ 
ture. We then resolved to pursue the inquiry 
together on the occasion of my next visit to 
England; and after the meeting in Glasgow 
