THE RECAPITULATION THEORY 337 



compared with other vertebrates, is one of the very 

 few points that can be referred to as possibly indi- 

 cating degeneration, and will be considered more 

 fully at a later point in my address. 



A consideration of much less importance, but 

 deserving of mention, is that in its mode of life 

 Amphioxus not merely differs as already noticed 

 from those groups of animals which we know to 

 be degenerate, but agrees with some at any rate 

 of those which there is reason to regard as primi- 

 tive or persistent types. Amphioxus, like Balano- 

 glossus, Lingula, Dentalium, and Limulus, is marine, 

 and occurs in shallow water, usually with a sandy 

 bottom, and, like the three smaller of these genera, 

 it lives habitually buried almost completely in the 

 sand, into which it burrows with great rapidity. 



I do not wish to speak dogmatically. I merely 

 wish to protest against a too ready assumption of 

 degeneration ; and to repeat that so far as I can 

 see, Amphioxus has not yet, either in its develop- 

 ment, in its structure, or in its habits, been shown 

 to present characters that suggest, still less that 

 prove, the occurrence in it of general or extensive 

 degeneration. In a sense, all the higher animals 

 are degenerate ; that is they can be shown to 

 possess certain organs in a less highly developed 

 condition than their ancestors, or even in a rudi- 

 mentary state. Thus a crab as compared with 

 a lobster is degenerate in the matter of its tail, 

 a horse as compared with Hipparion in regard to 

 its outer toes ; but it is neither customary nor 

 advisable to speak of a crab as a degenerate animal 



Y 



