ORIGIN OF MAN AND THE OTHER VERTEBRATES. 605 



Docimastes ensifer of Venezuela (Fig. 22, I), that of the female being 

 eight, of the male ten centimetres long. Fig. 22, II, shows a flower 

 of the datura species freqented by the last-named ; we here see how 

 the length of the beak and that of the corolla correspond. 



We thus see that in the tropics there are not only wind and insect 

 fertilized flowers, as with us, but also certain which are bird-fertilized, 

 i. e., plants in which the transference of the pollen is effected by hum- 

 ming-birds. 



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ORIGIN OF MAN AND THE OTHER VERTEBRATES. 



By Professor EDWAED D. COPE. 



THE early part of this century saw the establishment of most of 

 the fundamental principles of the science of physics, especially 

 as applied to astronomy. A few decades later saw the science of 

 chemistry emerge from the empirical and enter the jjhilosophical stage. 

 It has been reserved for the second half of the century to witness the 

 discovery of the facts and principles of the history of life on the 

 earth. The public mind is gradually awakening to the fact that the 

 grandest truths of creation are being placed within their reach by 

 the researches of contemporary science, and that the knowledge of 

 the manner of the origin of the human race is no longer withheld 

 from us. 



The study of the fossil remains of animals has revealed an immense 

 number of forms of life which in former ages have peopled the world. 

 The study of geology has shown that the history of our planet is 

 marked by successive deposits in water, which have become beds of 

 rocks. The relation of these beds to each other gives us the relations 

 of the animals and plants whose fossil remains they contain. Thus 

 we have obtained a consecutive history of life from its early appear- 

 ance to the present day. Before the doctrine of evolution was under- 

 stood, the successive populations that filled the successive periods 

 were supposed to have been the products of special creations. Now 

 it is believed, with the best of reason, that all forms of life have been 

 produced by changes of structure which arose in the course of descent, 

 the one species coming from the other ; and that interruptions in the 

 series of species from older to later periods are simply due to the 

 absence of the means of preserving their remains at certain times 

 during the course of the history of the world. These interruptions 

 indicate periods of dry land, since fossils are not preserved unless 

 they are excluded from the air by a covering of water or of mud. 



It is one of the peculiar advantages of the North American Con- 

 tinent to the scientist that the geological structure of its great interior 

 is comparatively simple, so that its history can be easily read. It fol- 



