﻿PRIMARY TYPES. 



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typical characters of the Annulosa is precisely that of 

 the class of birds ; and both are distinguished, in their 

 pre-eminently perfect examples, by having a body fur- 

 nished with wings. A shellfish is the type of the 

 Testacea, just as serpents are of the Reptilia ; and both 

 these are without feet or fins, yet crawl upon their bellies. 

 The Acrita and the Amphibia are the least organised of 

 their own circles ; while the animals of the Radiata, 

 like the fish, are pre-eminently aquatic. In this way 

 has Nature represented the great divisions of the animal 

 kingdom, in the class of Aves ; and has given us, under 

 the form of a bird, another modification of that which 

 we see in a butterfly, 



(7.) We have now sufficiently illustrated the station 

 which the circle of birds occupies in the animal kingdom, 

 and the analogies which belong to it as a class. Before, 

 however, we proceed to explain the primary groups 

 which compose this circle, let us advert to what has already 

 been said on the primary types of nature, and see how 

 far they are exemplified, or how far they can be traced 

 in the objects before us. This investigation will be 

 doubly instructive. It will tend to verify, in detail, those 

 assertions which have been advanced in a general way; 

 it will also awaken the attention of the ornithologist to 

 many peculiarities of structure and of habit ; and enable 

 him, even in the investigation of species, to refer many 

 shades of variation to one and the same cause, which 

 would either pass unregarded, or be considered altogether 

 anomalous. 



(8.) The primary types to which birds, no less than 

 all other animals, as we conceive, may be referred, have 

 been already expatiated upon.* But we are now to 

 regard them only as they appear in one class ; and their 

 definitions will consequently lose much of that vague- 

 ness, and be stript of many of those exceptions, which 

 it was impossible to avoid, when attempting to reconcile 

 the innumerable variations they assumed in the different 

 groups of the entire animal kingdom. The names by 



* Classification of Animals, p. 241. 

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