AFRICAN LONG-TAILED NIGHT-JAR. 6? 



with those words which pass from mouth to mouth, 

 like current coin, through the republic of science. 

 The same reasons, however, do not apply to the 

 vernacular name; and, therefore, while we retain 

 Caprimulgus, we may very well substitute the old 

 English name of Night-jar for that of Goat-sucker. 



It is only of late years that two or three of the 

 most remarkable forms in this intricate family have 

 been detached under separate names; while the 

 great mass of the species have been left in the same 

 state as they were in the days of Linnasus. This, 

 indeed, has been the case with more than one 

 family,^ but in the present it has been productive of 

 peculiar confusion and perplexity. We have already 

 had occasion to advert to the drongo-shrikes, as 

 being one of those groups wherein a close similarity 

 of colouring pervades nearly all the species, and 

 the remark is still more applicable to the family 

 before us. 'We might almost say, that in regard to 

 colour, if a person has seen one species of Capri- 

 mulgm, he has seen all. There are, it is true, 

 trifling variations, but these are sometimes so slight 

 that none but an acute ornithologist would detect 

 them ; while, from their veiy nature, they are so 

 difficult to describe, that the most laborious descrip- 

 tions fail to convey these differences to the mind of 

 the reader ; the different shapes of the marks, band, 

 and spots, the manner in which they are blended, 

 and the diversity of tints under which the different 

 colours of brown, grey, rufous, and whitish appear, 

 often upon a single feather, in these party-coloured 



