54 



corded to have given (with a single 

 combed $) 2 s.c , 1 r., 1 p. and 1 r.p. 

 This 9 was again tested in 1905 (Ex- 

 periment 334) and gave with a Br. L. 

 $ 7 s., 2 r., 2 p., and 3 r.p. There is, 

 therefore, no doubt that 9 Malays as 

 well as 6 s. can give off all four kinds 

 of gamete. Unfortunately we were un- 

 able to procure a $ Malay of this 

 nature in 1905, and the absence of 

 roses and singles in pure Malays must, 

 for the present, remain unexplained. 



SWEET PEAS 



Bush X Cupid Cross 

 The Bush Sweet Pea, a form not 

 previously used in these experiments, 

 has a peculiar conformation. After 

 reaching a height of about 8 inches it 

 branches profusely from its lower 

 nodes. Of the stems thus formed about 

 10—15 grow on, eventually reaching a 

 height of some 3 Vz feet. The produc- 

 tion of branches continues, but those 

 formed later remain short and slender. 

 In an ordinary tall Sweet Pea only 

 about four or five stems attain any 

 considerable extension (without spe- 

 cial treatment). The stems of the Bush 

 are thin and rather wiry, especially at 

 the base, and the plants, till they reach 

 a height of about 1 8 inches, can almost 

 maintain themselves erect without 

 sticks. By that time the stems are mu- 

 tually entangled by their tendrils, and 

 the compact bush-like form is very 

 pronounced, entirely distinguishing 

 them from any other sort of Sweet 

 Pea. 



In both the ordinary tall plants and 

 the ordinary Cupids there appears to 

 be some factor which restrains the 

 production of branches, and thus en- 

 ables the plant to attain a greater 

 length. The non-branching tall plant 

 attains a height 2 or 3 feet greater 

 than that of the Bush, which must be 

 regarded as a branching "tall." Sim- 



BATESON AND PUNNETT 



ilarly, the erect or branching Cupid 

 is more stunted in its length than the 

 ordinary or non-branching Cupids. 

 The allelomorphs concerned are evi- 

 dently:— 



Dominant 



1. Tallness (T) 



2. Prostrate: 



non-branching 



(P) 



Recessive 

 Dwarf ness (t) 

 Erect: branch- 

 ing (p) 



The ordinary tall is TTPP, the 

 prostrate Cupid is ttPP, and the Bush 

 is TTpp. When Bush is crossed with 

 Cupid the two complementarv^ factors, 

 T and P, necessary to the production 

 of the full height, meet each other and 

 the "reversion on crossing" occurs. 



In Fo, besides the three forms al- 

 ready mentioned with which we were 

 familiar, there appears also, in conse- 

 quence of the recombination of the 

 factors, a new type— the erect dwarf 

 (ttpp). These little plants have a very 

 singular appearance, being extremely 

 short and erect, somewhat resembling 

 box-edging. 



The numbers in the Fo generation 

 from six Fi plants were: 



The observed numbers approach 

 closely to those calcukited on the 

 9:3:3:1 ratio, and the case is evi- 

 dently one of dihybridism in which 

 the two pairs of factors concerned are 

 those we have suggested above. 



The families resulting from this 



