BIRD-LIKE QUADRUPEDS. 279 



instances in a brief manner, and without going into many details. 

 The Duck-mole, (p. 53, fig. 26,) or Ornithorhynchus, is the lowest 

 of all living Mammalian quadrupeds, and has such a peculiar 

 combination of characters in its organization as to have induced 

 Lamarck to pronounce it as neither a Quadruped nor a Bird. 

 Not only are its jaws toothless, but they are covered by a horny 

 sheath shaped like a duck's bill ; its young are born in a soft 

 shell, in the same way as are the young of birds and reptiles, 

 and it has spurs on its hind legs like a fowl ; and, finally, in cor- 

 respondence with these characters, its internal organization, in 

 some points, is almost identical with that of birds. 



What, then, shall we say of all these degrees of relationship; 

 shall we admit that the child is like the parent because the 

 parent gave it birth, and transmitted its features to it as an hered- 

 itary link) or must we look upon the parent as the mere impo- 

 tent covering by which the young is protected whilst it develops 

 certain foreordained characters, the most remarkable of which is 

 the resemblance to the animate enclosure from which it finally 

 emerges ? When we admit that the several members of one 

 family, which had one common parent, have individual differ- 

 ences by which they can be distinguished, the one from the other, 

 we begin to acknowledge that the same parent does not invaria- 

 bly project the same line of influences upon each of its offspring, 

 at each successive birth. Let now the influence, in any one line, 

 be projected by the offspring upon its young, and each of the 

 several offspring of the latter project the influence which it has 

 inherited, and each one of the resultants of these, at the same 

 time, transmit another set of influences, and so on from parent to 

 child, and child to grandchild, and from grandchild onward ad 

 inftnitum, and in the course of time the offspring of the long past 

 progenitor would hardly be recognized as of the same race. 



Thus I think it is, that, by the multiplication and intensifying 

 of individual differences, and the projection of these upon the 

 branching lines of the courses of development from a lower to 

 a higher life, the diverse and successively more elevated types 

 of each grand division have originated upon this globe. 



