MILESTONES OF EVOLUTION 45 



of a few species, and the skin has become as smooth as 

 glass, and with a dull polish. 



Now we have good reason to believe that their remote 

 ancestors wore armour, concealed, perchance, with a 

 scanty covering of hair. And this because, in the first 

 place, certain fossil species, known as zeuglodonts, which 

 were at any rate nearly related to the whale tribe of 

 to-day, certainly had such an armour ; and in the second, 

 traces of armour are actually present at any rate occa- 

 sionally in adults of the common porpoise, where the 

 dorsal fin is studded with bony bosses, and in another 

 (tropical) species, Neomeris, where rows of bony plates 

 are found running all the way down the back, embedded 

 in the skin. These can certainly serve no useful purpose 

 to-day, and must be regarded as remnants, vestiges, of 

 a more perfect armature worn by the generations of long 

 ago. 



The correctness of this surmise receives considerable 

 confirmation when \ve turn to the embryos of these por- 

 poises, for in both the bony remains are relatively much 

 larger than in the adults, in which, it is plain, they are 

 gradually disappearing. We may venture to prophesy 

 that in the course of a few more thousand generations all 

 record of their presence wiU be lost in the adults, and 

 after a still greater lapse of time in the embryos as well. 



The revelations of the dissecting-room seem hardly 

 likely to furnish material that could be of any interest 

 save to the specialist. And in truth the mere record of 

 facts obtained from such a source makes but a useless 

 catalogue. In mentally turning over its pages we find 

 ourselves asking, " Can these dry bones live ? " But 

 after a little while more and more items on the list leap 

 to the eyes, each witla a message. Those which more 



