4^ PKOCEKDINGS OF THE 



I iicidoutally I may refer to two points raised by those w ho object 

 to connecting the origin of Vertebrates with the Arthropoda. It 

 was represented that the cliitinous envelope of the latter' was 

 prohibitive of cilia. The delicate auditory cilia of Crustaceans are 

 well known to carcinologists, but I am warned by intelligible 

 signals that the term cilia is variously applied in dilf.^rent branches 

 01 Natural History. Another objection was founded on the diffi- 

 culty of believing in the transfer of function f.om one or^^an to 

 anoth'-r, as required by Dr. Gaskell's hypothesis. Jiut on this 

 head the ingenuity of A'ature seems to have been signally 

 vindicated by the lato Professor Gegenbaur, who showed how one 

 part of an animal organism, in proportion as it went out of servic3 

 for one function, could be appropriated for another. 



Now, on the general question we have admired Dr. Smith 

 AV'oodward's interesting account of the earliest fossil fishes. But 

 these are accepted Vertebrates. For the origin of Vertebrates we 

 must go back to something that is not a Vertebrate, such as may 

 have existed perhaps far back in the Laurentian period. Imagine 

 some soft, more or less elongated, animal organism wriggling about 

 in the primeval sea. Then, as now, tlie hard conditions°of the 

 AVorld demanded some sort of hardening on the part of living 

 creatures. Some would find advantage in a stron^^er external 

 coating, others in a strengthened central axis. ]iut in either ease 

 the necessity of wriggling would often be paramount, giving rise 

 on the one liand to a segmented exoskeleton, on the other to a 

 jointed backbone. In these wrigglers, Mr. President, you have 

 the origin of the Vertebrates,— a theory which it will be difficult 

 to refute, as the supposed animals have liitherto revealed absolutely 

 no relics. 



The President having called upon Dr. Gaskell to replv, that 

 gentleman said : — 



It is impossible for me in the short time at my disposal to deal 

 thoroughly with all the speakers in the two days' discussion. I will, 

 however, do what I can. 



Prof. MacBride in his latest paper prefers, as he said many years 

 ago, to attribute my explanation to my diabolical ingenuity." As 

 I have stated in my book, there is absolutely no ingenuity on my 

 part; given the one fixed point that the infundibulum represents 

 the old oesophagus and the animal remains upright, all the resem- 

 blances between the two groups of animals to which I have drawn 

 attention, naturally follow. The devil is not in mv ingenuity but 

 in Nature's facts. I can symuathize with MacBride, for surely 

 there could not be a more diabolical trick than to create from a 

 lowly organised unsegmented animal whole groups of animal's 

 becoming more and more segmented, all characterised by the 

 presence of an alimentary canal ventral to the nervous system, and 

 then wipe them off the face of the earth, so that no trace of this 

 setjuence of forms is left among li\ ing animals. Not content 



