TVPICAL GROUPS CONNECTED. 
57 
blance (we will neither term it analogy nor affinity) 
between Egithalus and Vermivora fully as strong as 
that between Mniotilta and Egithina ? We should cer- 
tainly say it is: again, supposing neither Mniotilta 
nor Egithina had been discovered, and we had no 
suspicion that such forms existed, in what manner 
should we suppose that the genera VaTun and Sylvicola 
were united by direct affinity ? In such a case, we 
should undoubtedly point to Vermivora, as passing into 
Parus by means of Egithahis, So close, indeed, is the 
resemblance between the two, that nothing but a slight 
difference in their wings and feet serves to separate 
them. Can then a resemblance, which, in such a case, 
is sufficiently strong to constitute an affinity, be termed 
a mere analogy? we think not: on the contrary, we 
believe, that in proportion as we contract our views, 
and investigate the nature of the typical or external 
groups in small circles, we shall find they follow each 
other in absolute affinity. It is needless, however, to 
