LES ENCHA1NEMENTS DU MONDE ANIMAL 101 



in the primitive Marsupials, in the Proboscidians, 

 in the Suidae, in several families of Carnivora ; they 

 become simplified in most of the Eocene Ungulates, 

 in the toothed Cetacea, or Cetodonts. The pre- 

 molars increase in complication with the Tapirida, 

 the Lophiodontidse, the Palseotheridse, the Equidae ; 

 they become reduced and simplified with the 

 Cervidse, the Bovidse, and generally with the Rumi- 

 nants. Very simple in structure with one or at 

 most three denticules in the majority of the Mam- 

 mals of the Secondary or the commencement of the 

 Tertiary, the teeth acquire, at the same epoch, in the 

 Multituberculata, the highest degree of complication 

 ever realized. Similar contradictions abound in 

 the history of palaeontology. They lead us scienti- 

 fically to observe a wise reserve towards the deduc- 

 tions, brilliant but too often deceptive, which can 

 be drawn from the state of evolution of an organ 

 or even of a group of organs in fossil animals. 



Together with the general exposition of his prin- 

 ciples of transf ormist philosophy, Gaudry took pains, 

 either in his special monographs or in his work on 

 the Enchainements du Monde Animal, to accumulate 

 manifold proofs of the gradual transition from one 

 genus to another, from one family to another family, 

 and even from one large group to another large 

 group, often at a great distance. According to him, 

 naturalists were first struck by the differences exist- 

 ing between beings and had rather too much ne- 

 glected the resemblances, whence the necessity 

 for modern palaeontologists to turn their minds 

 to the approximations. These resemblances Gaudry 

 sees everywhere, and sometimes, by dwelling on 



