R. C. PUNNETT 231 



result of such n mating. It is hoped to make this experiment in the 

 course of the present year^ 



The results of the matings among the F^ agouti-blacks are shewn 

 in Table VI, from which it appears that the results obtained from this 

 series of matings are in fair accordance with the theoretical expectation. 



TABLE VI. 



M«le B 144 M*le C 32 Male D 122 M&le D 128 



Na of Ag.- Ag.- Ac.- Kg.- 



Female BIk. Blk. Ag. ?« Blk. BlL Ag. ?» Blk. Blk. Ag. ?* Blk. BIk. Ag. 



B76 9 7 3 — — — — — — — — — — — — 



B151 8 1______ 2 2 2 — — — — 



B198 5 1 1 3 5852 — — — — — — — 



C 144— — — — 3414 — — — — — - — 



2) 20 — — — — 641— — — — — 4 3 3 



2) 21— — — — 4323 — — — — 5 5 1 



D145 ____13 72— — — — — — — — 



D 156— — — — 443— — — — — — — — — 



I>191____ 421— — — — — 4 2 1 — 



D 237— — — — 555— — — — — 6 1 3 1 



£35____ 563— — — — — 4 2 2 1 



22 9 4 3 49 43 23 9 2 2 2 — 23 13 10 6 



Black Agouti-Black ? « Agouti 



Totals 96 67 18 39 



11 7 



Amended totals ... 107 74 — 39 



Expectation ... 96-25 82-5 41-25 



In order to test the agouti-blacks further with respect to the factor 

 E both does and bucks were crossed with F^ heterozygous yellows, and 

 the does also with pure tortoise. Since the gametes of the agouti-black 

 are DEA, DEa, dEA, dEa, and those of the F2 yellow deA, dea, the 

 expected result of such a cross is given in Fig. 3. 



The expectation is blacks and agoutis only in the ratio 5 : 3. Tables 

 VII and VIII shew that only blacks and agoutis resulted from such 

 a cross, the actual numbers being 69 black and 33 agouti where the 

 expectation was 64 black and 38 agouti. 



^ Since the above was written an F3 black ? made in this way has been shewn to 

 be of the constitution DDEEJIa.. Crossed with a buck of the constitution ddSSaa she 

 has given only blacks and agouti-blacks. Among the 14 young so bred from her there was 

 no agouti. 



* The rabbits placed in this category were blacks which died too early to determine 

 whether they were true blacks or agouti-blacks. In making the amended total they have 

 been distributed pro rata among these two classes. 



