"70 SECTIONAL ADDRESSES. 



inch by inoK, through a single small group of strata. Only thus could 

 he base on the laboriously collected facts a single true Interpretation ; 

 and to those who preferred the broad path ol generality his Interpreta- 

 tions seemed, as Bacon says they always ' must seem, harsh and 

 discordant — almost like mysteries of faith.' 



It is impossible to read these words without thinking of one 

 'naturae minister et interpres,' whose genius was the first in this 

 country to appreciate and apply to palaeontology the Novum Organon, 

 Devoting his whole Ufe to abstruse research, he has persevered \yith 

 this method in the face of distrust and has produced a series of brilliant 

 studies which, whatever their defects, have illuminated the problems of 

 stratigraphy and gone far to revolutionise systematic palaeontology. 

 Many are the workers of to-day who acknowledge a master in Sydney 

 Savoiy Buckman. 



I have long believed that the only safe mode of advance in palae- 

 ontology is that which Bacon counselled and Buckman has practised, 

 namely, ' uniformly and step by step.' Was this not indeed the prin- 

 ciple that guided Linnaeus himself? Not till we have linked species 

 into lineages, can we group them into genera; not till we have un- 

 ravelled the strands by which genus is connected with genus can we 

 draw the limits of families. Not till that has been accomplished can 

 we see how the lines of descent diverge or converge, so as to warrant 

 the establishment of Orders. Thus by degrees we reject the old slippery 

 stepping-stones that so often toppled us into the stream, and foot by foot 

 we build a secure bridge over the waters of ignorance. 

 : The work is slow, for the material is not always to hand, but as we 

 build we learn fresh principles and test our cuiTent hypotheses. To 

 some of these I would now direct your attention. 



Continuity in Developvient. 



Let us look first at this question of continuity. Does an evolving 

 line change by discontinuous steps (saltations), as when a man mounts 

 a ladder; or does it change continuously, as when a wheel rolls up- 

 hill ? The mere question of fact is extraordinarily difficult to determine. 

 Considering the gaps in the geological record one would have expected 

 palaeontologists to be the promulgators oi the hypothesis of discon- 

 tinuity. They are its chief opponents.' The advocates of discon- 

 tinuity maintain that palaeontologists are misled : that the steps are so 

 minute as to escape the observation of workers handicapped by the 

 obscurities of their material ; that many apparent characters are com- 

 pound and cannot, in the case of fossils, be subjected to Mendelian 



1 As Dr. W. D. Matthew (1910, Pop. Sci. Monthly, p. 473) has well 

 exemp'lified by the history of the Tertiary oreodont mammals in North America, 

 the known record, taken at its face value, leads to ' the conclusion that new 

 species, new genera and even larger groups have appeared by saltatory evolution, 

 not by continuous development.' But a consideration of the general conditions 

 controlling evolution and migration among iand mammals shows him that such 

 a conclusion is unwarranted. ' The more complete the series of specimens, 

 the more perfect the record in successive strata, and the nearer the hypothetic 

 centre of dispersal, the closer do we come to a phyletic series whose intergrading 

 stages are weM within the limits of observed variation of the race.' 



