212 INHERITANCE, FERTILITY, AND SEX IN PIGEONS. 



It will be seen, then, in this case, that we got nothing out of the pair of birds 

 which is not in them to start with; when we have once learned that simple lesson 

 we can begin to calculate what will happen in the case of any new cross. It is not 

 now a matter of so great curiosity to me when I cross a pair of birds of different 

 species; I can usually forecast in a general way what the result will be. 



The next hybrid to be considered had an altogether different parentage, in so 

 far as the male parent is concerned. The mother was the same species of ring-dove 

 and the father a common pigeon the homer. The homer differs from other 

 common pigeons mainly in the size of the beak, which has a basal portion large as 

 compared with the ordinary pigeon. The hybrids 5 (pi. 32 and text-fig. 2) have also 



5 The hybrids shown in the plates have other common pigeons, not homers, MS sires. EDITOR. 



EXPLANATION OF PLATE 33. 



Figs. 1-6. The Nicobar pigeon, Catenas nicobarica. Habitat: From the Nicobars and Mergui 

 Archipelago through Malay Archipelago as far as Solomon Islands (Salv., p. 617). Natural 

 size. Hayashi del., Feb. 1903. 



The feathers of the side of the neck (the region of the neck-mark in other pigeons) are much elongated. A similar 

 elongation is seen in the hackled partridge (see Latham, Hist, of Birds, Vol. VIII, pi. cxxix, p. 307). These long 

 feathers are 37 mm. long (some are longer in Nicobar). When erected they appear like those on the neck of the ruffled 

 heath cock. 



Neck-feathers (left side). 



Fig. 1, from just under ear-coverts. Fig. 2, from middle of upper breast. Fig. 3, from just above middle of side. 

 Fig. 4, from same height on mid-back of neck. Fig. 5, from middle of side of neck. Fig. 6, entire head and neck, 

 f natural size. 



Figs. 7, 8, 9, 10, four feathers from neck of an adult male Coluinba guinea, and four feathers, figs. 11, 12, 13, and 

 14, from neck of a hybrid between a male C. guinea and a female C. lioia. X 2. Hayashi del., Apr. 1903. 



The split or bifurcation is stronger in the male parent, while the iridescence is stronger in the hybrid, as we should 

 expect, since C. livia is much more iridescent than C. guinea. 



7 and 11. Taken (in each case) just below ear coverts on the left side; these are red and bifurcated 



in the parent, but gray and entire in the hybrid. 



8 and 12. From near mid-height, side of neck. Longer and slenderer, and red in the male; wider 



and shorter, and gray in the hybrid. The split is longer in male, about equal in width. 



9 and 13. From near lower boundary of bifurcated feathers on side of neck (in line with 1 and 2) ; 



split wider in the male. 



10 and 14. From still lower. Little bifurcation in the male; none at all in the hybrid. 



EXPLANATION OF PLATE 34. 



Figs. 1, 2, 3. Adult male St. risoria (DSpil. suratensits (I) X St. alba (j) hybrid (T 1). From egg 

 of May 1, 1903. X 2 Toda del., April 1904. 



Fig. 1. The neck-mark, here shown flat, is smaller than in the male parent figured on this plate, figs. 4-0. The 

 divided tip of the feathers is also here less marked than there. The neck-mark and divided tip of the suralcnsis grand- 

 parent have thus been twice divided. The extent of the white tip on the feathers of the mark has also suffered two 

 reductions from suralensis toward the ring-dove. 



Fig. 2. Fifth feather, third row (right side). 



Fig. 3. Second feather, fifth row (right side). 



Figs. 4, 5, 6. Neck-mark of adult male hybrid between a male ring-dove hybrid and a female 

 Surate turtle-dove. X 2. Hayashi del., Nov. 1902. 



Sire: Streptopslia alha-risoria x St. risoria-alba (D 2). Dam: Spiloiiclia swatcnuis (Tt). Hybrid (F) hatched 

 Sept. 25, 1800. 



Fig. 4. This hybrid may be compared with St. risoria, Spil. tigriiui, and Spil. chine/mis, the latter being practically 

 the same as >>';/. xnmti-iiRis in its neck-mark. 



The rows are reduced in number and extent and the bifurcation is intermediate between the parents. It is in the 

 middle region that the black ring lakes most effect, some of the feathers tending here to lose the white tips. The 

 coalescence includes about 2 rows plainly; i.e., about half as much as chinensis. This hybrid shown in color plate 25, 

 fig. H; his dam in pi. 24. 



Fig. 5. First of fifth row, right side. The right (front) half is gray with long vinous tip; the left web is differen- 

 tiated and shortened, but only gradually. 



Fig. li. Kighth feather, fourth row (corresponds with fifth row in T. chinensis) left side. This shows full differen- 

 tiation, and narrow white tips. 



