THE MUTATION THEORY AND MUTATIONS. 165 



tional nature is left somewhat in doubt) was more clearly like the mutant father 

 than its mutant nest-mate; the latter lived much longer and was unquestionably 

 like its father in respect of the mutational characters. The description of these 

 birds when 14 days old, follows: 



The color of MN 1 is nearly the usual guinea-red, but the characteristic white apical 

 spots are more grayish and hence not so conspicuous as in the typical Columba guinea. 

 In some feathers there is a bare trace of such marks, but not enough to amount to anything 

 in determining the pattern. 



The second young (MN 2) — dead at 14 days- — is closely like a young rock-pigeon of 

 the same age, but there are no bars. The white spots (guinea-marks) are present but 

 rather light grayish in color. The feathers are not far enough along to make sure whether 

 these white spots are to extend over the whole wing. The coverts at the fore end of the 

 wing are not red, but grayish brown — nearly the color seen in the spotted pigeon 13 (C. 

 maculosa). The posterior coverts are paler gray — nearly the shade of young rocks of the 

 same age, but lighter. 



The feathers of the breast are dark brown, of nearly the same shade as that in C. 

 affinis. The feet and legs are a little more blackish than in young rocks of the same age. 

 The beak is darker than in the rock. I think this bird would have been nearly an inter- 

 mediate between the guinea-pigeon and the rock-pigeon, except for a lack of wing-bars. 

 I can not be sure on this point, for bars at this age are not to be seen in the common pigeon. 



At 6 weeks the other young (MN 1) was again described as follows: "This bird 

 is now 6 weeks old lacking 1 day. The photograph (101) was taken November 7, 

 1910, at the age of 4 weeks, and is now being colored by Mr. Toda. The bird was 

 taken into the house, to be brought up by hand, when between 3 and 4 weeks old. 

 It has been 'remarkably tame' from the first. I have kept it in a small cage with 

 a young rock-pigeon and a Japanese turtle of the same age. The young rock and 

 turtle-dove learned very quickly — within a day or two — to eat seed without help, 

 but the young guinea insisted on my feeding it by opening its beak and crowding 

 in seed. He is so tame that he sits half-asleep on the artist's finger while his picture 

 is being colored. 



"On November 21, at the age of 6 weeks, I again photographed this young guinea 

 alongside a juvenile normal guinea (of 10 weeks) to show that the white spots are 

 much sharper and whiter in the normal than in MN l. u I note these further differ- 

 ences: (1) the reddish tips of the feathers of the basal half of the neck are very weak 

 in MN 1 and conspicuous in the normal. In the normal these reddish tips run up 

 to and over the top of the head. (2) The 'vinous-chestnut' of the chequers of 

 the wings is darker in MN 1 than in the normal, as we should expect. 15 (3) The head 

 is smaller and darker gray in MN 1 than in the normal. (4) I think the skin around 

 the eye is smaller in MN 1 than in the normal. The color of this skin is darker 

 gray — about that of the feathers of the head in shade." 



The following word concerning this bird (MN 1) can be added by the editor: 

 During 1911 the rock-pigeon and the Japanese turtle, referred to above, were left 

 with this "remarkably tame" C. guinea, until late summer, when the rock was 



" This species has much "gray" and little " red" in its plumage; i.e., has much of the gray ground-color of Columba 

 lima; see plate IS. — Ed. 



14 Apparently no prints from these negatives were ever made; the author's last illness began 9 days later. When 

 the need of this illustration became evident the negatives were no longer available to the editor. 



15 That is, the color approaches that of the chequers of the rock-pigeons. — Ed. 



