372 RICHARD OWEN xxn 



information mainly based upon original observations and 

 dissections. It is in fact a collection of nearly all his 

 previous memoirs arranged in systematic order, generally in 

 the very words in which they were originally written, and 

 unfortunately sometimes without the revision which advances 

 made in the subject by the labours of others would have 

 rendered desirable. Very little of the classification adopted 

 in this work, either the primary division of the Vertebrates 

 into Haematocrya and Hsematotherma, or the divisions into 

 classes and sub-classes, has been accepted by other zoologists. 

 The division of the Mammalia into four sub - classes of 

 equivalent value, upheld by Owen, not only in this work, but 

 in various other publications issued about the same time 

 (Kede Lecture, etc.), founded upon cerebral characteristics, was 

 especially open to criticism. Though the separation of the 

 Monotremes and Marsupials from all the others as a distinct 

 group (Lyencephala) is capable of vindication, the three other 

 sub-classes, Lissencephala, Gyrencephala, and Archencephala, 

 grade so imperceptibly into each other that their distinction 

 as sub-classes cannot be maintained. The proposed definition 

 of the distinguishing characters of the brain of Man (Archen- 

 cephala) from that of other Mammals gave rise to a somewhat 

 acute controversy, the echoes of which reached beyond the 

 realms of purely scientific literature. On the other hand, the 

 radical distinction between the two groups of Ungulates, the 

 odd -toed and the even -toed, first indicated by Cuvier, when 

 treating of the fossil forms, was thoroughly worked out by 

 Owen through every portion of their, organisation, and remains 

 as a solid contribution to a rational system of classification. 



The chapter called " General Conclusions " at the end of 

 the third vohime is devoted to a summary of his views on the 

 principal controverted biological questions of the day, especially 

 in relation to the teaching of Darwin, just then coming into 

 great prominence. Although from the peculiarly involved 

 style of Owen's writing, especialy upon these subjects, it is 

 sometimes difficult to define his real opinions, it appears that 

 before the publication of the Origin of Species, he had 

 " been led to recognise species as exemplifying the continuous 

 operation of natural law, or secondary cause, and that not only 



