36 R. A. EMERSON 
five classes is 5.6 and for the sixth class is 17. The probability that such 
deviations as occur are due to chance is approximately 0.35, or more 
than one in three. The eight self-pollinated plants gave together the six 
types in frequencies as follows: 
Dilute Dilute 
purple sun red 
Ta ita tla Ve V-. Viasbae 
Color types Purple Sun red Brown Green Total 
Observed =... 193 66 60 16 57 34 426 
Calculated..... 180 60 60 20 60 46 426 
Difference. .... +13 sine 0 —4 —3 —12 0 
The probability that such deviations as occur may be due to errors 
of random sampling is practically 0.27. Similar deviations might there- 
fore be expected somewhat more than once in four trials. It will be 
noted that two progenies lacking class IV are included in this lot (group 1, 
table 8). The total number of plants in these progenies were 37 and 
17, respectively, and they should therefore have had, respectively, two 
and one plants in class IV. 
Five F; purple plants (group 2, table 8) gave four color types (Ia, Ia, 
IIIa, and IVa) in F;, with total frequencies as shown below. Here the 
probability, P, equals 0.75, indicating that deviations of this magnitude 
might be expected thru chance in three out of four trials. The com- 
parison of observed with theoretical distributions follows: 
Dilute Dilute 
Color types Purple Sun red © : ; Total 
purple” sunied gap eos 
Ta Ila Illa IVa 
Observed sae = ss ee 102 36 29 13 180 
Calculatedsr 2s. 2s 101 34 34 11 180 
WDITeTENCE Aas Aceh es spl +2 —) +2 0 
Progenies of seven other purple F2 plants (group 3, table 8) consisted 
of the four color types Ia, Ila, V, and Vla. Four of these F: plants were 
self-pollinated and gave a total of 164 F; plants. Four, including one that 
was also selfed, were backcrossed to green and yielded a total of 209 F; 
plants. For the progenies from selfed F: plants P=0.20, and for those 
from backcrossed plants P=0.57. There is, therefore, one chance in five 
