MODERN SCIENCE. 123 



lake- basin \vhere he found the Dinocerata, the series of 

 fossil horses which enabled him to prove the present horse 

 to be descended from the small five-toed Eohippus (see 

 Darwin), one of the most beautiful and conclusive examples 

 of the law of animal evolution (1870). By the side of the 

 animals above-mentioned innumerable snakes, crocodiles, 

 tortoises, fishes, marsupials, rodents, insectivorous and carni- 

 vorous types, were also found, the species of which were for 

 the most part unknown before. Prof. Marsh, it is hardly 

 necessary to add, has enriched the Yale College Museum, 

 which he has to a great extent reorganised, by countless 

 specimens of all kinds the Pterodactyls alone are repre- 

 sented by more than 600 individuals, the Mosasaurs by 

 1,400! Marsh handsomely acknowledges the earnest help 

 he received in his labours from Mr. T. B. Hatcher, his 

 assistant, without whose energy and skill some of his ex- 

 plorations would have proved fruitless. To the whole of 

 the work we just attempted to describe, Prof. E. D. COPE, 

 of the Pennsylvania University, and Prof. Joseph Leidy, both 

 American scientists of distinction and learning, have con- 

 tributed their share, especially as regards the Vertebrates 

 of the Cretaceous and Tertiary formations. 



Such is the glorious record of American science within 

 the last twenty or twenty-five years. 



PHYSIOLOGY. 



1628 1694. Malpighi, by means of the MICROSCOPE, im- 

 mensely extended the scope of anatomy and physiology, 

 revealing minute structures hitherto unsuspected ; discovered 

 the CAPILLARIES microscopic tubes connecting the arteries 

 with the veins an additional evidence of Harvey's theory ; 

 also the AIR-CELLS and their membranes in the lungs, from 

 which the blood derives its oxygen and rejects carbonic acid, 

 thereby explaining what was so mysterious even after 

 Harvey. Malpighi studied the tongue and carefully described 

 its vessels, nerves, and coverings ; also the SKIN, discovering 

 its several parts the epidermis, the MALPIGHIAN LAYER, 

 which contains the pigment which colours the skin, the 



