DARWIN 319 



by the comparison of embryonic stages of higher 

 animals with the adult forms of lower animals 

 (Meckel, von Baer), and by the succession of 

 [extinct] species in time. In some of his lectures 

 he is said to have held that a limited degree of 

 degeneration is due to disuse. He concludes : 



How inherited, or what ma}^ be the manner of 

 operance of the secondary cause in the production of 

 species, remains in the hypothetical state exemplified 

 by the guess-endeavours of Lamarck, Darwin, Wal- 

 lace, and others. 



Toward the end of his life Owen apparently 

 relaxed this attitude of hostility toward modern 

 Evolution, for in discussing Platy podosaurus^ he 

 says r 



One may also conjecture, on the derivative hy- 

 pothesis, that the higher class of Vertebrates, as 

 represented by the low ovoviviparous group now lim- 

 ited to Australasia, may have branched off from a 

 family of Triassic Reptilia represented, and at pres- 

 ent known only, by the fragmentary evidences of 

 such extinct kinds as that which forms the subject of 

 the present communication. 



iQuart Journ. Geol. Soc, vol. XXXVI, 1880, p. 423. 



^Letter to author from Doctor Robert Broom. Doctor Broom 

 also writes (July 28, 1928): "I had a letter from Owen in 1890— 

 two years before his death — in which he quite approved of a sug- 

 gestion of mine that the thickened epithelium on the jaws of 

 early mammalian foetuses probably represented the remains of a 

 honey -sucking beak in the ancestral young. The theory may be 

 quite wrong, but certainly shows that Owen in 1880-1890 thought 

 in terms of Evolution." 



