292 COURTSHIP ACTIVITIES IN THE RED-THROATiSD DIVER. 
MoTTEAM. '14. Controlled Natural Selection and "Value marking. London, Longmans, 
Green & Co., 1914. 
OwBN. '16-'22. Brit. Birds, x., xii., xv. (Sparrow-Hawk.) 
Pease. '22. Proc. Cambr. Philos. Soc. xxi. p. 22. 
PiKB. '13. Brit. Birds, vii. p. 148. (Crested Grebe.) 
PouLTON. '08. Essays on Evolution. Oxford, 1908. (pp. 379, 386.) 
Pychaft. '13. The Courtship of Animals. London, 1913. 
Sedlitz. '13. Journ. f. Ornith. cxi. p. 179. (Black-throated Diver.) 
Selotts. '01-'02. Zoologist (4), v. & vi. (Crested Grebe ; Peewit.) 
Selous. '02. Zoologist, 1902, p. 196. (Reversed pairing in Moorhens.) 
Selous. '05 a. The bird watcher in the Shetlands. London, 1905. (pp. 122-126.) 
(Mutual courtship.) 
Selous. '05 i. Bird-life Glimpses. London, 1905. (p. 296.) (Dabohick.) 
Selous. '09. Zoologist (4), xiii. & xiv. (Blackcock.) 
Selous. '12 a. Zoologist (4), xvi. p. 81 ; xvii. p. 210. (Red-throated Diver.) 
Selous. '12 6. Zoologist (4), xvi. p. 197. (Origin of Display.) 
Selous. '1-3. Zoologist (4), xvii. (pp. 294, 409). (Swans.) 
Selous. '14. Zoologist (4), xviii. p. 73. (Great Northern Diver.) 
Selous. '15. Wild Life, vii. (Dabchick.) 
Stctbtevant. '15. Journ. Aniiu. Behaviour, v. p. 353. (Drosophila.) 
Turner. '13. Brit. Birds, vii. p. 150. (Red-throated Diver.) 
Van Oobdt & Huxley. '22. Brit. ]5irds, xvi. p. 34. (Red-throated Diver.) 
Whitman & Riddle. '19. Carnegie lust. Pub., Washington, 1919. (Pigeons; Doves.") 
WiTHEHBY. '00. Ibis, 1900. (Red-throated Diver.) 
EXPLANATION OF THE PL.ITES. 
Plate 14. 
-Fig. 5. Louisiana Heron {Hydranassa tricolor). Twig-bringing ceremony after nest-relicf. 
The relieved bird is presenting a twig to the bird on the nest. Note raising of 
crest, aigrettes, and neck-feathers, and spreading of wings. 
-Fig. 6. Nest-relief ceremony of Little White Egret (Egretta candidissuna). The bird on the 
right is about to step off the nest. Note erection of crests and aigrettes, and 
spreading of wings. 
Plate 15. 
Fig. 7. Two female Whitethroats (6'y/i)M COTcrea) fighting for a male aid his territory; 
the male watching. 
Fig. 8. A pair of Willow- Warblers {Fhylloseopus trochilas) ; simultaneous performance of 
wing-flapping ceremonj'. 
