334 



THE AMERICAN NATURALIST [Vol.XLVII 



appear in spots, i. e., a factor analogous to the factor 

 commonly recognized as the white spotting factor. 



In the following crosses some tortoise colors appeared. 

 A tortoise is black-and-red with no white. 



Tricolor black, 410 $, by red, 339 c?, gave four tortoise, 

 viz., 536, 537, 538, 539. 



Bicolor black, 423$, by red, 339 c?, gave two tortoise, 

 540 (with white blaze — not in figure) and 541. 



Tricolor black, 413$, by a self-black, 341c?, gave one 

 uniform red. 



Tricolor black, 491 $, by same, 341 £, gave black, 551. 



Tricolor black, 513? (nearly bicolor black), by same 

 male, gave uniform black, 590, and uniform red, 591. 



Black, 471$ (out of 401$,. by 309c?), by father, 309c?, 

 gave black, 518 and 519. Later when mated to another 

 self black, 341c?, she gave red, 547, 548; black, 549. 



Bicolor red, 509$ (nearly red?), by bicolor black, 535 

 (nearly black), gave tricolor black, 581, and tricolor in- 

 termediate, 532 c?. These two opposite bicolors gave tri- 

 colors and so far as 502 is concerned two animals almost 

 completely pigmented over the posterior half of the body 

 produced a young that was white in these parts. Simi- 

 lar relations might have been pointed out in the other 

 crosses; but reverse cases also occur. 



Tortoise Inter Se, Etc. 



Tortoise, 538$ and 536$, by 537 c?, gave two bicolor 

 reds, 583, 580; two uniform red, 584, 585. It would ap- 

 pear that tortoise, while not showing white may carry 

 it in the same way in which a uniform animal may carry 

 it. It is also striking that the result is like that obtained 

 in F 2 from the mating of 401 tricolor black, to self-color 

 red, although the F 2 is somatically very different. 



Tortoise, 524$, by uniform black, 341c? (never crossed 

 with spotted animals as far as known), gave tortoise, 

 566, and red, 567 (not on charts). 



Tortoise, 524, by uniform black, 341, gave bicolor 

 black, 587 (almost uniform), and two tortoise, 588 

 and 589. 



