THE BELFAST ADDRESS. 471 
The Igde of discovery once struck, those petrified forms 
in which life was at one time active, increased to multitudes 
and demanded classification. They were grouped in 
genera, species, and varieties, according to the degree of 
similarity subsisting between them. Thus confusion was 
avoided, each object being found in the pigeon-hole 
appropriated to it and to its fellows of similar morphological 
or physiological character. The general fact soon became 
evident that none but the simplest forms of life lie lowest 
down; that, as we climb higher among the superimposed 
strata, more perfect forms appear. The change, however, 
from form to form was not continuous, but by steps some 
small, some great. "A section," says Mr. Huxley, "a 
hundred feet thick will exhibit at different heights a 
dozen species of Amnionite, none of which passes beyond 
the particular zone of limestone, or clay, into the zone 
below it, or into that above it." In the presence of such 
facts it was not possible to avoid the question: Have these 
forms, showing, though in broken stages, and with many 
irregularities, this unmistakable general advance, being 
subjected to no continuous law of growth or variation? 
Had our education been purely scientific, or had it been 
sufficiently detached from influences which, however 
ennobling in another domain, have always proved hindrances 
and delusions when introduced as factors into the domain 
of physics, the scientific mind never could have swerved 
from the search for a law of growth, or allowed itself to 
accept the anthropomorphism which regarded each suc= 
cessive stratum as a kind of mechanic's bench for the 
manufacture of new species out of all relation to the old. 
Biased, however, by their previous education, the 
great majority of naturalists invoked a special creative 
act to account for the appearance of each new group of 
organisms. Doubtless numbers of them were clear-headed 
enough to see that this was no explanation at all- 1 that, in 
point of fact, it was an attempt, by the introduction of a 
greater difficulty, to account for a less. But, having 
nothing to offer in the way of explanation, they for the 
most part held their peace. Still the thoughts of reflect- 
ing men naturally and necessarily simmered round the 
question. De Maillet, a contemporary of Newton, has 
been brought tTTto notice by Professor Huxley as one who 
" had a notion of the modifiability of living forms," The 
