y underlying the seeming diversity
of Nature is here exemplified, as elsewhere in the writings of Erasmus
Darwin; and, more specifically, a clear grasp of the essentials of the
function of respiration is fully demonstrated.

ZOOLOGY AT THE CLOSE OF THE EIGHTEENTH CENTURY

Several causes conspired to make exploration all the fashion during the
closing epoch of the eighteenth century. New aid to the navigator
had been furnished by the perfected compass and quadrant, and by the
invention of the chronometer; medical science had banished scurvy, which
hitherto had been a perpetual menace to the voyager; and, above all, the
restless spirit of the age impelled the venturesome to seek novelty in
fields altogether new. Some started for the pole, others tried for a
northeast or northwest passage to India, yet others sought the great
fictitious antarctic continent told of by tradition. All these of course
failed of their immediate purpose, but they added much to the world's
store of knowledge and its fund of travellers' tales.

Among all these tales none was more remarkable than those which told of
strange living creatures found in antipodal lands. And here, as did not
happen in every field, the narratives were often substantiated by the
exhibition of specimens that admitted no question. Many a company of
explorers returned more or less laden with such trophies from the
animal and vegetable kingdoms, to the mingled astonishment, delight, and
bewilderment of the closet naturalists. The followers of Linnaeus in the
"golden age of natural history," a few decades before, had increased the
number of known species of fishes to about four hundred, of birds to one
thousand, of insects to three thousand, and of plants to ten thousand.
But now these sudden accessions from new territories doubled the figure
for plants, tripled it for fish and birds, and brought the number of
described insects above twenty thousand. Naturally enough, this wealth
of new material was sorely puzzling to the classifiers. The more
discerning began to see that the artificial system of Linnaeus,
wonderful and useful as it had been, must be advanced upon before the
new material could be satisfactorily disposed of. The way to a more
natural system, based on less arbitrary signs, had been pointed out by
Jussieu in botany, but the zoologists were not prepared to make headway
towards such a system until they should gain a wider understanding of
the organisms with w