STUDIES ON THE GENETICS OF FLOWER-COLOURS, ETC. 
117 
see some form of linkage, and on the other the free assortment of the gametes. 
Experiments for determining all such important points were already begun. 
Some further breeding has been performed in respect to the present cross, 
but I will here simply state shortly what I have found about the reds in 
F,. Of 20 reds in all which have appeared in F,, only two could be selfed, 
and their offspring ( = F A ) were examined; the results were as follows:— 
Magenta 
Red 
Orange 
Totals 
No. 1 
It 
32 
9 
42 
» 2 
24 
14 
'38 
Totals 
1 
56 
23 
89 
Expected 
0 
60±3-8 
29+3-8 
89 
Hence we see that both reds examined are heterozygous in respect to It, 
i. e. CCUrbb. When JÏ and I* are linked in the ratio 5: 1: 1 : 5 or 
6 :1:1: 6 we should have CCJRvbb : CCItllbb in the ratio 10:1 or 
12 : 1 respectively, and thus there is no wonder that we have met with no 
homozygous reds at all, because only two reds were examined. 
Multiple Allelomorphism. 
One of my objects of investigation of the flower-colours of Portulaca was 
to pursue, if we have there a case of the so-called “ multiple allelomorphism ” 
of Morgan and his school : thus white, orange, flesh-colour, yellow, red and 
magenta in our varieties might be a series of multiple allelomorphs which 
occupy the corresponding loci in certain homologous chromosomes. We have 
however above seen that the results of all crosses in Portulaca executed by 
me are very well explainable by means of usual unit factors. The following 
remarks might also be of some interest. If my experiments in Portulaca 
had ended with the /^-generation, we might perhaps be led in certain 
cases at least to conclude that we have then to deal with a case of multiple 
allelomorphism. For instance, I have found that the /^-offspring ex redx 
t This magenta came to development, because at least one gamete CRB was produced 
by reversion. Similar facts were observed in respect to No. 24 (Table VIII), -generation (dis¬ 
cussion, p. 129) and No. 29 (same Table, discussion p. 127). 
