32 THE DOCTRINE OF DESCENT. 



Cuvler believed them to be more nearly related, and 

 introduced them altogether, under the name of Radiata. 

 This similarity, however, is only superficial, for whilst, 

 on the one hand, anatomy discloses the great difference 

 of the Ccelenterata and Echinodermata, the history of 

 evolution still more decidedly banishes the Echinoderm 

 from this position, and connects them more closely with 

 the next division. 



In this, that of the Vermes, the systematizer of the 

 old school finds his real difficulty ; in so many ways do 

 they deviate from each other, so great is the distance 

 between the lower and the higher forms ; and after 

 deducting the distinctive marks of orders, so- little 

 remains as a common character, so variegated is the 

 host of smaller scattered groups, and even of single 

 species, which demand admittance to the system of the 

 Vermes. If we attempt to describe their typical nature 

 in a few words, it rnust be something like this : The 

 Vermes are more or less elongated, symmetric animals, 

 which possess no actual legs, but effect their locomotion 

 by means of a muscular system, closely combined with 

 the integuments, which frequently become an actual 

 muscular cylinder. To this we will add, that the per- 

 plexities and difficulties in reference to points of classi- 

 fication are transformed into sources of knowledge for 

 the adherent of the doctrine of Descent. 



The relations of the previous family with the type of 

 the Articulata is so conspicuous, that the " kinship " 

 of the two was never questioned, even by the older 

 zoologists. The very name of one, the highest division 

 of the Vermes, that is, of the Annelids, or segmented 

 worms, indicate this connection. This distinctive mark 



