340 DARWINISM STATED BY DARWIN HIMSELF. 



ing bats determine the existence of the larger naturalized 

 quadrupeds in seTeral parts of South America. 



Pa e 295 ■"■ ^^^ repeat what I published in 1845, 

 namely, that to admit that species generally 

 become rare before they become extinct — ^to feel no sur- 

 prise at the rarity of a species, and yet to marvel greatly 

 when the species ceases to exist, is much the same ae to 

 admit that sickness in the individual is the forerunner of 

 death — to feel no surprise at sickness, but, when the sick 

 man dies, to wonder and to suspect that he died by some 

 deed of violence. 



DEAD LINKS BETWEEN LIVISTG SPECIES. 



No one will deny that the Hipparion is 

 intermediate between the existing horse and 

 certain older ungulate forms. What a wonderful con- 

 necting link in the chain of mammals is the Typotherium 

 from South America, as the name given to it by Professor 

 Gervais expresses, and which can not be placed in any 

 existing order ! The Sirenia form a very distinct group 

 of mammals, and one of the most remarkable peculiarities 

 in the existing dugong and lamentin is the entire absence 

 of hind limbs, without even a rudiment being left ; but 

 the extinct Halitherium had, according to Professor 

 Flower, an ossified thigh-bone "articulated to a well-de- 

 fined acetabulum in the pelvis," and it thus makes some 

 approach to ordinary hoofed quadrupeds, to which the 

 Sirenia are in other respects allied. The cetaceans or 

 whales are widely different from all other mammals, but 

 the tertiary Zeuglodon and Squalodon, which have been 

 placed by some naturalists in an order by themselves, 

 are considered by Professor Huxley to be undoubtedly 



