HETEROMERI—HOACTZIN 421' 



xanthochroism ; Avhile blue, in the absence of the colour-producing 

 surface, may appear brownish or grey. The pale coloration of 

 "Desert-forms" {swpra, p. 336), and the seasonal and sexual changes 

 of colour in many species, though perhaps ultimately referable to 

 acts of Heterochrosis, are not covered by this term since they are 

 now become normal features (see Colour, p. 99). 



HETEROMERI, Garrod's name {Proc. Zool. Soc. 1876, pp. 517, 

 518) for a group composed of Cotingidm (Chatterer) and Pipridie 

 (Manakin) which differ from most other birds in having the 

 femoral artery developed instead of the sciatic, wherein they are 

 opposed to the Homceomeri, but both combined form his 

 Mesomyodi, 



HETEROMORPH^, Prof. Huxley's name {Proc. Zool. Soc. 

 1868, p. 311) for an ornithological section consisting, so far as 

 known, of a single genus, Opisthocomus (Hoactzin). 



HEWEL,! HEWHOLE, HICKWALL and HIGH-HOLDER, 

 names given in various places to a Woodpecker of one kind or 

 another. The first two are said to be corrupted from the third,- 

 the older form of which, " Hickwaw " (Hollyband) and " Hickway," 

 " Heigh -ha we " and " Highawe " (Cotgrave), can hardly have come 

 from anything but the Anglo-Saxon Higera or Higere (T. Wright's 

 Vocabularies, pp. 29, 62, 281) meaning a laugher, and doubtless 

 referring to the cry of the Green Woodpecker, Gecinus viridis. 

 Hewhole was, however, in use in 1544, as shewn by Turner, who 

 Latinized it Huhola ; and in North America it has taken the further 

 modifications of High -hole and High -holder for the FLICKER 

 (Audubon, Orn. Biogr. i. p. 191 ; Ingersoll, Bull. Nuttall Club, 1881, 

 p. 184). For further information on these and other English 

 synonyms of Woodpecker see Yarrell {Br. B. ed. 4, ii. pp. 461-463).^ 



HOACTZIN or HOATZIN, a bird of tropical South America, 

 thought by Buffon to be that indicated by Hernandez under these 

 names, the OpistJiocomus hoazin or 0. cristatus of modern ornitho- 

 logists — a very curious and remarkable form, which has long 

 exercised the ingenuity of classifiers. Placed by Buffon among his 

 '' Hoccos " (Curassow), and then by P. L. S. Miiller and Gmelin in 



•' For this Andrew Marvell on (Nun) Appleton House (lines 557 et seqq.) may 

 be cited. 



- If Hewhole be a corruption of Hickwall it has been obviously brought in by 

 the bird's habits ; but we must not forget that Holzhauer is a German equivalent 

 (Bechstein, Gemeinn. Naturgesch. Deiitschl. ii. p. 1007). 



^ The derivations of the many names of the Woodpecker in the earlier 

 editions of Yarrell's work are extremely erroneous, being the work of some 

 anonymous authority in days before the study of. words was placed on a sure 

 basis. 



