1874.] Tropical Zoology. 321 
or no he received ‘‘the salary of an ambassador and the 
treatment of a gentleman,” he scatters before us, broadcast, 
facts, interesting and novel; valuable hints for future re- 
search, and generalisations which will amply repay a close 
examination. Not alone the zoologist, the botanist, the 
geologist, but the antiquarian, the ethnologist, the social 
philosopher, and the meteorologist, will each find in these 
pages welcome additions to his store of knowledge and sound 
materials for study. With all this, the work is not a mere 
dry catalogue of facts, such as Henry Cavendish might 
have written: it is eminently a “‘ readable book.” ‘Though 
without any effort at fine writing, the beautiful forest land- 
scapes of Central America are brought vividly before us. 
For instances, we refer our readers to the work itself. 
In his professional investigations of the gold deposits of 
Chontales, the author was struck with the scarcity of 
alluvial gold in the valleys, even in the neighbourhood of 
rich veins of auriferous quartz. This fact, reminding the 
observer of the similar scarcity in the valleys of Nova Scotia 
and North Wales, can be explained ‘‘on the supposition 
that the ice of the glacial period was not confined to extra- 
tropical lands, but, in Central America, covered all the 
higher ranges and descended to at least as low as the line of 
country now standing at two thousand feet above the sea, 
and probably much lower.” That glaciers would have this 
‘effect is indubitable. As the author remarks: ‘‘ When the 
denuding agent was water, the rocks were worn away, and 
the heavier gold left behind at the bottom of the alluvial 
deposits; but when the denuding agent was glacier-ice, the 
stony masses and their metallic contents were carried away, 
or mingled together in the unassorted moraines.” 
We may, at first sight, feel sceptical concerning the ex- 
istence of glaciers in the low grounds within 13° of the 
equator. But the testimony of the rocks appears irresist- 
ible. ‘‘ The evidences of glacial action were as clear as in 
any Welsh or Highland valley. There were the same 
rounded and smoothed masses of rock, the same moraine- 
like accumulations of unstratified sand and gravel, the same 
transported boulders that could be traced to their parent 
rocks, several miles distant.’’ Glacial scratches were not, 
indeed, observed; but these are rarely detected on surfaces 
of rock exposed to the atmosphere. We must, also, remem- 
ber that Professor Hart has found glacial drift extending 
from Patagonia all through Brazil to Pernambuco, whilst 
the late lamented Agassiz has observed glacial moraines up 
to the equator. On a former journey Mr. Belt discovered in 
