212 INHERITANCE, FERTILITY, AND SEX IN PIGEONS. 



It will be seen, then, in this case, that wc get nothing out of the i^air of liirds 

 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 jiigeon — 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 ^ (pi. 32 and text-fig. 2) have also 



5 The hybrids shown in the plates have other common pigeons, not homers, as sires.— Editor. 



Explanation of Plate 33. 

 Figs. 1-6. The Nicobar pigeon, Cptenas nicobarica. Habitat: From the Nicot)ars and Morgui 

 Archipelago through INIahiV Archipelago as far as Solomon Islands (Salv., p. ()17). Nattn-al 

 size. Hayashi del., Feb. 1903. 



The feathers of the side of tlie neck (the region of the neck-mark in other pigeons) are niucli elongatetl. .\ simihir 

 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 car-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. 0, entire head and neck. 

 i natural size. 



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

 14, from neck of a hybrid between a male C. guinea and a female C. livia. 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 \\i' sliould 

 expect, since C. liuia is much more iridescent than C. guinm. 



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

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



8 and 12. From near mid-height, side of ii<ck. Lonurr and .slenderer, and red in the male; wide 

 and shorter, and gray in tlic li\ biiil. Tlic split is longer in male, about equal in \vi ' 



9 and 13. From near lower boundary ol l)ifureatcd leathers on side of neck (in line with 1 ;ind 2); 

 split wider in the male. 



10 and 14. From still lower. Little 



Explanation of Plate 34. 

 Figs. 1, 2, 3. .\dult male Hi. rison'a {\)-Spil. suratensis ({) X St. alba (i) li\-l)rid (T 1 ). Vvmn egg 

 of May 1, 1903. X 2 Toda ,1,1., .\pril 1904. 



Fig. 1. The neck-mark, here shouii llii, i< -m ill, r than in I he male parent figured on this plate, figs. 4-(>. The 

 divided tip of the feathers is also here l,ss innrkiMl I liiiii tli,-rc. Tin- neck-mark and divided tip of the sumlen^ii grand- 

 parent have thus been twice divid,',!. The extent of the white lip on tlie feathers of tlie mark has also suffered two 

 reductions from surah i,s,.- t.,w,inl the ring-dove. 



Fig. 2. Fifth featli.r, (l.i.,l inw (right side). 



Fig. 3. Second featlur, lijili 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: Streplopelia atha-risoria x SI. risoria-alba (D 2). Dam: Spilopclin Kuratcnaiii (I'l). llyl>rid (,F) hatched 

 Sept. 25, 1899. 



Fig. 4. This hybrid may be compared with St. risoria, Sjiil. lijjriiui. and SpU. chincnsia, the latter liemg practically 

 the same as Spil. surale7isis in its neck-mark. 



The rows are reduced in number and extent and the bifmcal M>ri i- inliriiiediate between the parents. It is in the 

 middle region that the black ring takes most effect, some of ih, I. Mth, r- l,nding here to lose the white tips. The 

 coalescence includes about 2 rows plainly; i.e., about half as mu,li as rlun, /,s/.s. This hybrid shown in color plate 25, 

 fig. B; 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 difteren- 

 tiated and shortened, but only gradually. 



Fig. 6. Eighth feather, fourth row (corresponds with fifth row in T. chinensis) left side. This shows full differen- 

 tiation, and narrow white tips. 



