THE LATERAL NECK-SPACE. 33 



occur on the other spaces. Moreover, the character of many spaces changes at the breeding 

 season. At this period portions of the spaces on the breast and belly of a great many birds 

 usually lose all the down with which they are clothed at other times, notwithstanding that 

 the skin is at the same time very full of blood ; they thus acquire naked spaces, to which Faber's 

 name of brood-spots may be applied. These occur in the females, and also frequently in the 

 males, according as the incubation of the eggs is performed by the two sexes alternately or by 

 the former alone. 1 



Let us now examine the different spaces above mentioned. 



I. THE LATERAL NECK-SPACE ( Apterium colli laterale). 



This is essentially only a continuation of the lateral space of the trunk, and is indicated by a 

 distinct name merely for facility of description. Ascending on each side of the neck, between 

 the cervical portion of the spinal tract and the gular portion of the inferior tract, it extends, in 

 most birds, scarcely beyond the middle of the neck, but in some cases reaches the head, and in 

 the Owls (Plate II, figs. 8 and 11) only terminates close to the chin. I find it shortest in the 

 Uiiffiiirostres (Plate X, fig 7), Steyanopodes (Plate X, figs. 8 and 9), and in some Waders, c.y. 

 Platdea. It is entirely deficient in the Herons (Plate VIII) and Storks (Plate IX), where its 

 place is occupied by the lateral neck-tract, whilst the rest of the surface of the neck is a space. 

 In the birds with continuous neck-plumage, such as Opisthocomus (Plate VI, figs. 12 and 13), 

 also, it does not occur. 



In all long-necked birds, in which that part of the body is curved in the form of an S, 

 so that the head rests between the high shoulders, the latter insert themselves in these lateral 

 neck-spaces as in a covert, and this reception of the shoulders seems to be the chief purpose of 

 the space. 



1 The brood-spots which I have had the opportunity of observing were generally situated in the 

 median inferior space, or also in the branch-like processes of the lateral spaces. I have, however, 

 ascertained that in some Owls even contour-feathers are destroyed in consequence of incubation, and 

 thus gaps are produced iu the inferior tracts. Faber and Brehm distinguish brood-spots according to 

 their number and position, and even employ them to characterise birds ; but their description of 

 them is inaccurate and valueless, as they do not notice the regular distribution of the feathers, nor 

 do they even state whether the brood-spots occur in the spaces or the tracts. Nor can this be deduced 

 from Faber's distinction between true and false brood-spots (' Ueber das Leben der hochnordischen 

 Vogel/ pp. 136, 138). He only states that the former occur solely on the bellies of some northern 

 aquatic birds, and are produced by the birds themselves by tearing out the feathers (whether down- 

 or contour-feathers is not mentioned) ; while the latter also appear on the breast, and are produced 

 by simple wearing away during incubation. I have most certainly seen the two brood-spots ascribed 

 by this writer to the species of Phalaropus between the lateral branch and the main stem of the 

 inferior tract, and have convinced myself of the spontaneous shedding of the down-feathers at this spot. 

 This may also be the case with the contour-feathers, when these are wanting at the period of incubation/ 

 as in the Owls (see that family). The birds may, however, in some cases pull out the feathers which 

 have already become loose, and thus assist in the production of the brood-spots. 







