THE ORIGIN OF VERTEKRATES. 1 69 



\vlieii the legs of the arthropod have disappeared, in order to 

 furnish either a rudder-like tail, or loco-motor hind-limbs, for 

 the purpose of providing- fresh means of locomotion. Without 

 such members the incipient vertebrate would fall back in the 

 scale of being behind the whelk and the oyster, and become 

 itothing better than a miserable sea-squirt ! 



In January and February. 19 lo. the Linnean Society held a 

 debate, or discussion, on Dr. Gaskell's theory, which occupied 

 two meetings of that body, during which it was considered from 

 the standpoints of embryology, comparative anatomy, palaeont- 

 ology, physiology, and even psychology. The speakers were 

 Prof. MacBride, Prof. Starling, Air. Goodrich, Dr. Smith Wood- 

 ward^ Prof. Dendy, Sir Ray Lankester, Dr. Chalmers Mitchell, 

 Rev. Mr. Stebbing, Dr. D. H. Scott, Dr. Gadow, and Prof. 

 Stanley Gardner. The last two largely supported Dr. Gaskell's 

 theory, but. speaking generally, although no counter theory was 

 definitely put forward, the meeting, as a whole, was unable to 

 accept that scientist's views, although those present expressed, 

 through Sir Ray Lankester, their appreciation of his observa- 

 tions. Dr. Gadow strongly supported Dr. Gaskell in rejecting 

 amphioxus as a lineal ancestor, a theory advocated by Mr. 

 Goodrich, who held that there would be no difficulty in deriving 

 the lamprey, or animoca:tcs, from an aiiiphio.vus-\\ke ancestor 

 by a normal process of evolution in which cephalisation wouM 

 take a leading part ; but, as to what preceded the aniphio.vus-Vike 

 ancestor, zoologists refused to commit themselves to an opinion. 

 Prof. Starling's objection to Dr. Gaskell's theory was opposed 

 by Dr, Smith Woodward. Generally, it appeared that, although 

 the majority were sceptical, they were so for different reasons, 

 and that the objections which appeared vital in the opinion of 

 one, did not appeal with any force to the other.* 



But when all is said and explained, is this theory, taken at 

 its fullest, more difficult to accept or understand than the well- 

 known facts of the metamorphosis of the tadpole into the frog, 

 the axolotl into the salamander, the leptocephalus into the eel? 

 Are the changes any more startling than those that take place 

 in the pupae of the lepidoptcra? 



* See "Nature," No. 2102. Vol. LXXXII. p. 445. 



