PUZZLES AND PATRIARCHS. 19T 



by hirn Palceospondylus gunni. It is a very small 

 fish and, it should be noted, shows no trace 

 either of jaws or limbs, so that if these have been 

 lost it must have been at some infinitely remote 

 period. But there is another side to this question, 

 for many and very eminent authorities hold that 

 the evidence of degeneration is more imaginary 

 than real, and that we are to regard the lamprey 

 as an exceedingly primitive type. 



This indecision as to the true nature of the 

 lamprey necessarily leaves the question of the 

 pedigree still a matter for debate. Many of 

 those who hold the lamprey to be a degenerate 

 fish consider that it is possibly closely akin to 

 the recent bony fishes. Whilst those who deny 

 its claim to rank as a fish at all, regard it as the 

 representative of the ancestral stock from which 

 the fishes took their origin. 



With the fossil forms, to which attention must 

 now be turned, there is the same indecision, the 

 same interpretation of facts, so as to demonstrate 

 opposite conclusions. The forms in dispute are 

 relics of a past exceedingly remote, dating back 

 in fact to the old Silurian epoch, and representing 

 the earliest record we have of vertebrate life on 

 the earth. Whether they are closely related or 

 not is uncertain. The feature that would im- 

 press the observer most on seeing one of these 

 fossils for the first time, would be the remarkable 

 development of the external skeleton, which 

 formed a more or less complete coat of mail. 

 Further examination would lead to the discovery 

 that in some there were no paired fins or limbs ; 

 whilst in others only the front pair were present, 



