112 
S. IKENO : 
priori very probable, I could find no such indication at the beginning of my 
experiment. On studying, however, the Ivgeneration of the present cross, I 
have found some reds in the offspring of one magenta id-parent (Table VI, 
B : Magenta, No. 6). This points out naturally towards the composite 
nature of the magenta factor, and I was able to establish the fact by the 
Cross-experiment VIII. 
Cross VIII. Magenta x orange. (PL II, fig. 1 and 3). 
CCBBBB x CCrrbb F L = CCBrBb. 
The id-hybrid beais magenta flowers (s. the Table of Colours, p. 96). 
The id-offspring are composed as in the followiug Table : — 
Table VII, A. 
F 2 -generation (1917). 
No. of No-offspring 
No. of F 1 -plants self eel 
Magenta 
Orange 
Total 
20 
151 
73 
221 
Expected 
168±6'5 
56+6-5 
221 
The deviation of the actual results from the theoretical calculated on the 3 : 1 
basis is 17, and consequently 2‘6 times the standard error ( = 6 - 5). Thus the 
actual results are not in very good agreement with the expected ; the chief 
cause of this discrepancy is in all probability to be sought in the poor 
germination of seeds, and I think that we have here in spite of discrepancy 
a case of segregation into 3 magentas and 1 orange. 1 The lack of reds in 
this case is evidently due to the absolute linkage of B and B, as it was the 
case in the Cross V, VI and VII, or at least to the linkage of very high 
intensity where so few reds are expected that they will not appear at all 
unless an enormous number of plants are in cultivation. 
Now what is very remarkable about the id-ofispring derived from the 
id-plants under discussion is the fact that some of the magentas have under- 
' We may have 1 such case out of about 112 trials as the result of random sampling. 
