^ SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I46 



Africa. Another race, pica, similar in color characters, but larger 

 in size (wings 149 to 164 mm. ; tail 173 to 197 mm.), has two discon- 

 nected breeding ranges ; one part breeds in Baluchistan, and in 

 northern India from the Kashmir Himalayas west to West Pakistan, 

 and Nepal, south to United Provinces, and Kutch, and winters 

 largely in Africa, south of the Sahara ; another large segment of the 

 subspecies breeds in sub-Saharan Africa from Senegal east to Ethio- 

 pia and the Somali Republic, southward to Angola, northern portions 

 of Northern Rhodesia, and southern Kenya. The third race serratus, 

 similar in size to pica, is dimorphic in the southeastern portion of its 

 range. Its pale morph is like pica but with the shaft streaks of the 

 throat and breast feathers darker and often heavier, and the entire 

 pectoral area and the sides of the body tinged lightly, or more 

 heavily, with grayish. The dark morph is black except for the white 

 wing patch. This is the race of Africa south of the Zambezi River, 

 where it occurs only during the breeding season, October to March, 

 wintering in tropical Africa along with pica and jacobinus. In the 

 western part of its breeding range, especially in South- West Africa, 

 it approaches in coloration the race pica; but the birds breeding there 

 agree better on the average with pale serratus, and, furthermore, 

 they lay white eggs like serratus {pica and jacobinus lay blue-green 

 eggs). There is reason to believe that serratus may breed north to 

 southern Kenya, but no form of the jacobin cuckoo has yet been 

 found to breed in Tanganyika. 



The chief evolutionary interest in the facts discussed in this section 

 is that the range of variation in C. levaillantii, from the heavily striped 

 pattern to the almost unstriped anterior underparts, as in the type 

 example of "caroli" and in the Tembura example, comes very close 

 to bridging the gap in this character between this species and C. 

 jacobinus (fig. 14). We have also seen that the range of variation 

 in the pale morph of the latter varies from birds with the chin, throat, 

 and breast entirely white, devoid of any streaks or marks, to others 

 with well-developed, but narrow, dusky shaft lines on the feathers 

 of these parts. The lack of greater difference between the most defi- 

 nitely lined jacobinus and the least striped levaillantii almost es- 

 tablishes a variational continuum. There is a more sizable break be- 

 tween the dimensional characters of the two, but here again, the gap 

 between the smallest levaillantii and the largest jacobinus is not very 

 great in proportion to their size. Also, the juvenal plumages of the 

 two species, and the melanistic phases are extremely similar, 

 save in dimensions. The eggshell color of C. jacobinus in India and 

 in northeastern Africa is similar to that of levaillantii. It is true that 



