THE BELFAST ADDKESS. 173 



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 Ammonite, none of which passes 

 beyond the particular zone of limestone, or clay, into the 

 zone below it, or into that above it.' Jn 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 intro- 

 duced as factors into the domain of physics, the scienti- 

 fic mind never could have swerved from the search for 

 a law of growth, or allowed itself to accept the anthropo- 

 morphism which regarded each successive stratum as a 

 kind of mechanic's bench for the manufacture of new 

 species out of all relation to the old. 



Biassed, 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 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 explana- 

 tion, they for the most part held their peace. Still the 

 thoughts of reflecting men naturally and necessarily 



