474 On the Latent Capacity for Mutation. 



of this plant made on me at first. I was at first inclined 

 to regard this phenomenon as local, like the actual muta- 

 tions, but had no opportunity to institute an investiga- 

 tion of the matter. Perhaps other observers in other 

 places will be able to fill up these gaps. The chief point 

 for my purpose is the proof that a high degree of her- 

 itable variability was actually in existence in the plants 

 in the field at Hilversum. 



Tricotyly.^ Tricotylous seedlings are fairly abundant 

 in my cultures; hemitricotyly, which simply consists in 

 the splitting of one of the cotyledons, is somewhat rarer. 

 I have onlv recorded these two abnormalities occasion- 



ml 



ally, as compared with the others, because I regarded 

 them as of little importance at first. The following 

 summary of the cases noted will however give data as 

 to their occurrence and frequency in the different fam- 

 ilies. 



I have started three experiments on the inheritance 

 of these abnormalities by sowing seeds of tricotylous 

 plants in three different families, of 0. nanella, 0. laevi- 

 folia and 0. ruhrinervis : in the latter only, however, was 

 the experiment continued through subsequent genera- 

 tions. 



In the following summary the years refer to the seed- 

 lings and not to the parent plants of the preceding har- 

 vest. 



In 1887 I got tricotyls from seeds collected at Hilver- 

 sum; one of them grew up as an 0. lata, but set no seed. 



In 1890 I found one tricotylous seedling in the chief 

 strain of the Lamar ckiana-i^mWy (p. 224), and in a crop 

 of one of its wa^^j/Za-subfamilies : the latter grew up as 

 a dwarf. 



^ See also the second volume. 



