6o BIOLOGICAL LECTURES. 



from this combined method of work, and it is devoutly to be 

 wished that its scope may be more and more extended. As an 

 example may be cited the recent investigations upon the 

 mammalian dentition. From palaeontological phyla we have 

 learned to distinguish the homologies of the cusps, and the 

 way in which a complex tooth is gradually formed from a 

 simple one. Embryology, on the other hand, has shown the 

 relations of the successive dentitions to one another in a 

 fashion that palaeontology could by no possibility accomplish 

 unaided. As another example may be mentioned Wincza's 

 discovery of a bony clavicle in the embryo of the sheep, which 

 was soon followed by the still more unexpected one of vestigial 

 bony clavicles in certain extinct artiodactyls, confirming and 

 explaining the first. Embryology has taught us that the large 

 element in the carpus of the Carnivora known as the scapho- 

 lunar was formed by the coalescence of three separate bones, 

 — the scaphoid, lunar, and centrale. Later the fossils were 

 unearthed, which showed that the embryonic and transitory 

 condition of the modern forms was the permanent and adult 

 structure of the primitive Eocene flesh-eaters. 



The more the combined method is employed the more 

 fruitful does it appear. Nor should the combination be 

 restricted to the technically morphological subjects. Experi- 

 mental embryology has already won some notable triumphs, 

 and that is a physiological quite as much as a morphological 

 province. 



In the ever-increasing complexity of modern civilization a 

 more and more important role is played by systematic coopera- 

 tion, specialists combining for joint work which neither could 

 accomplish alone. Is it Utopian to wish that some such 

 organized scheme of attack upon biological problems shall 

 be devised, when, instead of every man doing merely that 

 which is right in his own eyes, we shall combine in a definite, 

 orderly way to investigate a given topic in all its bearings 1 It 

 may well be doubted whether any naturalist, however great his 

 genius, will ever again be able to take such an exhaustive 

 survey of biological data as Darwin did in his time. The 

 enormous mass of accumulated facts already far transcends 



