352 THE ZOOLOGIST. 



the master's own, we hear him speak of what are still the great 

 problems and even the hidden m.ysteries of our science ; of such 

 things as the nature of variation, of the struggle for existence, of 

 specific and generic differentiation of form, of the origin of the 

 tissues, the problems of heredity, the mystery of sex, of the 

 phenomena of reproduction and growth, the characteristics of habit, 

 instinct, and intelligence, and of the very meaning of Life itself. 

 Amid all the maze of concrete facts that century after century keeps 

 adding to our store, these, and such as these, remain the great 

 mysteries of natural science — the Magnalia naturcB, to borrow a 

 great word from Bacon, who in his turn had borrow^ed it from 

 St. Paul. 



Not that these are the only great problems for the biologist, nor 

 that there is even but a single class of great problems in Biology. 

 For Bacon himself speaks of the magnalia naturce, quoad usus humanos, 

 the study of which has for its objects " the prolongation of life or 

 the retardation of age, the curing of diseases counted incurable, the 

 mitigation of pain, the making of new species and transplanting of 

 one species into another," and so on through many more. Assuredly 

 I have no need to remind you that a great feature of this generation 

 of ours has been the way in which Biology has been justified of her 

 children, in the work of those who have studied the magnalia naturce, 

 quoad usus humanos. 



But so far are biologists from being nowadays engrossed in 

 practical questions, in applied and technical Zoology, to the neglect 

 of its more recondite problems, that there never was a time when 

 men thought more deeply or laboured with greater zeal over the 

 fundamental phenomena of living things ; never a time when they 

 reflected in a broader spirit over such questions as purposive adapta- 

 tion, the harmonious working of the fabric of the body in relation to 

 environment, and the interplay of all the creatures that people the 

 earth ; over the problems of heredity and variation ; over the 

 mysteries of sex, and the phenomena of generation and reproduction, 

 by which phenomena, as the wise woman told, or reminded, Socrates, 

 and as Harvey said again (and for that matter, as Coleridge said, and 

 Weismann, but not quite so well) — by which, as the wise old woman 

 said, we gain our glimpse of insight into eternity and immortality. 

 These, then, together with the problem of the Origin of Species, are 

 indeed magnalia naturce, ; and I take it that inquiry into these, deep 

 and wide research specially directed to the solution of these, is 

 characteristic of the spirit of our time, and is the pass- word of the 

 younger generation of biologists. 



No small number of theories or hypotheses, that seemed for a time 

 to have been established on ground as firm as that on which we tread, 

 have been reopened in our day. The adequacy of natural selection to 

 explain the whole of organic evolution has been assailed on many 

 sides ; the old fundamental subject of embryological debate between 

 the evolutionists or preformationists (of the school of Malpighi, 

 Haller, and Bonnet) and the advocates of epigenesis (the followers of 



