ANIMAL KINGDOM. 323 



conclusion on this subject precipitately; and therefore, in 

 saying that there is a general tendency, in every natural 

 group of animals, to be subdivided into five others, I 

 would only have this opinion accounted an hypothesis 

 which is not entirely destitute of arguments wherewith 

 we may support its truth. Yet I must acknowledge that 

 it appears to me, even by what we have already seen, to 

 be so far established, that in future, where great chasms 

 occur in smaller groups, I shall consider myself entitled 

 to suppose that these proceed from our ignorance of the 

 productions of Nature. 



On surveying with attention the affinities as they are 

 expressed in the foregoing table, it also appears that the 

 animals which compose a circle are few, and that the great 

 bulk of living beings is in some measure to be reckoned 

 out of its circumference. Thus, let any naturalist regard 

 a man, a beetle, a medusa, a monas, and a snail, he will 

 find it impossible to connect them by any solid principles 

 of affinity without reference to some of the intervening 

 animals. Taken alone, they are five different and peculiar 

 pieces of mechanism, which scarcely possess any thing in 

 common but material life and irritability. The course of 

 the real Zoological circle is nearly perhaps as follows : 



Tunicata, Alcyonium, . . . Zoanthida, 



Acephala, Fistulida, 



Brachiopoda, Echinida, 



Cephalopoda, Cirripeda, 



Reptilia, Branchiopoda. 



Amphibia, Crustacea, 



Pisces, Annelides, .... Ametabola. 



And all out of the line of this series may be termed eccentric 

 groups, which indeed comprise the most perfectly con- 



y 2 



