52 



to 307, 309, 311 to 313, 315, 317 to 320, 

 323 to 327, 329, 331 to 332, 334, 342 to 

 343, 345 to 348, 359, 361 to 365, 373 to 

 374, 382, 386.) 



Of the 1,251 birds produced in the 

 above experiments 373 were r.p., 425 

 pea, 413 rose, and 440 single, expecta- 

 tion in each case being 413. There is 

 a marked deficiency of r.p. and a dis- 

 tinct excess of singles. These disturb- 

 ances in the expected ratio of equality 

 we are inclined to attribute to the 

 behaviour of the 4 5 s. used in Experi- 

 ments 306, 347 to 349, and 373 to 374- 

 cases which must be considered in 

 rather more detail. 



The $ s. in Experiments 306 and 

 349 gave only 10 r.p. birds out of a 

 total of 93, i.e., only half the number 

 expected, although the total number 

 of chicks hatched was fairly large. 

 These cases were not followed up, but 

 when the same phenomenon reap- 

 peared in Experiment 373, the $ bird 

 was mated also to 4 pure Br. L. 9 s. 

 (Experiment 374). Again, there was a 

 marked deficiency of r.p. chicks, 

 pointing to something unusual hap- 

 pening among the gametes of this $ . 

 The bird has been kept in order that 

 further experiments may be made next 

 year. 



Experiments 347 to 348 seem to 

 point to a disturbance of a somewhat 

 different nature. The $ (No. 144 of 



BATESON AND PUNNETT 



1904) was originally mated with 3 

 single combed 9 s. to test the nature 

 of his comb. Later on a black Andalu- 

 sian 9 and 2 Wh. L. 9 s. were intro- 

 duced. The $ turned out to be giving 

 off all 4 kinds of gametes, giving with 

 the 3 original 9 s. and the black An- 

 dalusian 18 s., 26 r., 26 p., and 25 r.p. 

 With the 2 White Leghorn hens, how- 

 ever, he gave an extraordinary defi- 

 ciency of r. and r.p., the numbers 

 being 17 s., 2 r., 17 p., and 3 r.p. 



In the case of each of these 4 birds 

 the numbers are so aberrant that we 

 can for the present hardly avoid re- 

 garding them as due to some disturb- 

 ing circumstances. The number of 

 chickens involved is 309, viz., 107 s., 

 75 r., 86 p., and 41 r.p. Subtracting 

 these numbers from the sum totals 

 given above, we are left with 333 s., 

 338 r., 329 p., and 332 r.p., which is 

 a very close approach to the expected 

 ratio of equality. 



Rose Pea-combs Mated Together. 



Zygote R. ?w P. P. no R. X zygote 

 R. no P. P. no R. In the last Report (p. 

 110) were mentioned four experiments 

 of this nature in which the figures ob- 

 tained were not far removed from the 

 expected ratio of 9 : 3 : 3 : 1. 



Further experiments of the result of 

 this type of mating were made in 1904, 

 and are set out in the table below: 



