AND THE BEGINNING OF REASON. l6l 



added those which are constituted by food and climate 

 and a multitude of changes and chances in the whole 

 course of its existence. Some characters it may derive 

 from remote ancestors, transmitted through, though 

 not developed in, its ' immediate progenitors/ It is 

 now forty years since two French anatomists showed the 

 possibility, or even probability, of a connection between 

 the molluscous cuttle-fish and the vertebrate type ; and, 

 considering the propensity of the highest vertebrate 

 for perpetually squirting ink at those who meddle with 

 it, most readers of controversy will think the instance 

 well selected. Those who wish to be told what the first 

 vertebrate was probably like, should first accurately 

 define what they mean by a vertebrate. Is a jointed 

 backbone the only essential? And if so, how many 

 vertebrae are essentially requisite ? A creature with 

 two vertebra would be as much a vertebrate as a creature 

 with three. What shall we say, then, of a creature 

 possessing, if we may use the expression, but a single 

 vertebra ? It would not have a jointed backbone. It 

 would not be a vertebrate. Yet, by the simple multi- 

 plication of similar parts, in accordance with a thousand 

 analogies, a vertebrate could be developed from it. By 

 the differentiation of these similar parts, which not only 

 might follow, but must follow, a great variety of species 

 could easily be evolved. Those who really take an 

 interest in the problems connected with this subject, 

 and whose ' convictions' are not too strong and absolute 

 to be swayed by ascertained facts and logical reasoning 

 will do well to study the ' Principles of Biology,' 



M 



