CONCLUDING REMARKS. 
199 
attending the investigation of these two groups, as well 
as that of the TrocMlidte, which is this; — that however 
naturalists may differ about the primary nature of other 
birds, they will be unanimous respecting these ; a par- 
rot or a woodpecker cannot belong to any other groups 
than their own; Nature herself has separated and 
characterised them from all others ; so that the investi- 
gator knows at once the extent of the group he has to 
deal with, and he has only to make out its internal 
relations. In short, 1 consider the Piciana; to he so 
perfect a circle, that I have been accustomed to view 
it, in all doubts and misgivings regarding others, as 
that upon which I could fall back, as upon a strong 
and impregnable hold, for demonstrating those first prin- 
ciples of the natural system I have, perhaps, too boldly 
announced. In regard to nearly all othere, I may em- 
ploy the words of two eminent writers who have had to 
contend with the same difficulties in the same line of 
inquiry. “ When we cannot represent Nature as she 
is, we must endeavour to represent her as she appears 
to be; for if we suspend our observations in appre- 
hension of committing an error, we shall soon cease to 
represent her at all.” * 
» mm. Horsfield and Vigors i Linn. Trans, xv. 328. 
