32 THE DOCTRINE OF DESCENT. 
Cuvier 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 must 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 
