Abrupt Origin of Species, 1 59 



or articulate, has been found. There are gaps every- 

 where. The ascidian, a mollusk, and the amphioxus, 

 a fish, have been dragged in to represent a transition 

 or bridge between mollusk and fish. But with such 

 unfortunate links as these, the same difficulty arises 

 as with all intermediate species interposed between 

 two widely separated ones. A criticism on a single 

 case like this may suit for all. I say then, it is like 

 bridging over a sea without a bridge: like finding 

 new islands everywhere, which require as many new 

 bridges. For species, to use Mr. Herbert Spencer's 

 idea, are only new clusters thrown out into space. 

 Or, like the shoots of a tree, the more there are, 

 the more the apices or points that shoot out towards 

 the sky. Yet the modern mind argues thus: "In 

 i860," says Professor Cope, " there were 250 species 

 of extinct mammals known: there are now some- 

 thing near 2000. I have found many myself." 

 That is to say, he must also have found many new 

 gaps between the newly-found species. Straight- 

 way, he goes on to infer by a " practical law of infer- 

 ence " that the gaps will all be filled up, or bridged 

 over for evolution to cross, because he has found 

 so many new species. But we may ask, how many 

 species new or old, all divided uncompromisingly 

 from one another, will make a connection or tran- 

 sition between any two ? However, this is the Pro- 

 fessor who requires only the rule, the measure, the 

 line, to determine what a species is or is not (No. 

 126). Another, who seems to understand something 



