Chap. vi. 
AFFINITIES AND GENEALOGY. 
213 
carry us on to the amphibians. We have seen that 
blr ds and reptiles were once intimately connected 
to getlier ; and the Monotremata now, in a slight degree, 
c °nnect mammals with reptiles. But no one can at 
Present say by what line of descent the three higher 
and related classes, namely, mammals, birds, and rep- 
t'lcg, were derived from either of the two lower verte- 
orate classes, namely amphibians and fishes. In the 
c 'lass of mammals the steps are not difficult to con- 
oeive which led from the ancient Monotremata to 
^e ancient Marsupials; and from these to the early 
progenitors of the placental mammals. We may thus 
^oend to the Lemuridee ; and the interval is not wide 
10111 these to the Simiadae. The Simiadse then branched 
into two great stems, the New World and Old World 
^°nkeys ; and from the latter, at a remote period, Man, 
10 wonder and glory of the Universe, proceeded, 
j J-hus we have given to man a pedigree of prodigious 
eil gth, but not, it may be said, of noble quality. The 
|'°rld, it has often been remarked, appears as if it had 
° n g been preparing for the advent of man ; and this, in 
? rie sense is strictly true, for he owes his birth to a long 
Jlle of progenitors. If any single link in this chain 
ad never existed, man would not have been exactly 
hat he now is. Unless we wilfully close our eyes, we 
ltla y, with our present knowledge, approximately re- 
°°guise our parentage ; nor need we feel ashamed of it. 
Je most humble organism is something much higher 
aa the inorganic dust under our feet ; and no one 
^th an unbiassed mind can study any living creature, 
°Wever humble, without being struck with enthusiasm 
lts Marvellous structure and properties. 
