272 Sir John Lubbock’s Address. 
caterpillars are full of interesting lessons; while, in other cases, 
specially among butterflies, Bates has made known to us the 
curious phenomena of mimicry. 
The science of embryology may almost be said to have been 
generalization that the development of the eg, 
progress from the general to the special, that zoological affinity 
is the expression of similarity of development, and that the 
different great types of animal structure are the result of dif- 
ferent modes of development—in fact, that embryology is the 
key to the laws of animal development. 
seems to be now generally admitted that birds have come down 
to us through the Dinosaurians, and, as Huxley has shown, the 
profound break once supposed to exist between birds and rep- 
tiles has been bridged over by the discovery of reptilian birds 
and bird-like reptiles; so that, in fact, birds are modified rep- 
tiles. Again, the remarkable genus Peripatus, so well studied 
by Moseley, tends to connect the annulose and articulate types. 
Again, the structural resemblances between Amphioxus and 
the Ascidians had been pointed out by Goodsir; and Kowa- 
levsky in 1866 showed that these were not mere analogies, but 
indicated a real affinity. These observations, in the words of 
Allen Thomson, “have produced a change little short of revo- 
lutionary in embryological and zoological views, leading as 
they do to the support of the hypothesis that the Ascidian 1s 
an earlier stage in the phylogenetic history of the mammal and 
other vertebrates.” 
The larval forms which oceur in so many groups, and of 
which the Insects afford us the most familiar examples, are, 10 
the words of Quatrefages, embryos, which lead an independent 
