178 ORIGIN OF NON-SEXUAL CHARACTERS 



was one called lata. It must be explained that 

 the young plant of (Enothera has practically no 

 stem, but a number of leaves radiating in all direc- 

 tions from the growing point which is near the 

 surface of the soil. The plant is normally biennial, 

 and in the first season the internodes are not 

 developed. This first stage is called the ' rosette.' 

 From the reduced stem are afterwards developed 

 one or more long stems with elongated internodes, 

 bearing leaves and flowers. In the mutation lata 

 the rosette leaves are shorter and more crinkled 

 than those of Lamarckiana, and the tips of the leaves 

 are very broad and rounded. The stems of the 

 mature plant are short and usually more or less 

 decumbent with irregular branches. The flower- 

 buds are peculiarly stout and barrel-shaped, with 

 a protrusion on one side. The seed-capsules are 

 short and thick, containing relatively few seeds, and 

 the pollen is wholly or almost wholly sterile. 



It is to be noted here, a fact emphasised by De 

 Vries in his earliest publications on the subject, that 

 in nearly all, if not all cases, a mutation does not 

 consist in a peculiarity of a single organ, but in an 

 alteration of the whole plant in every part. In this 

 respect mutations as observed in (Enothera seem to 

 be in striking contrast to the majority of Mendelian 

 characters. Mutation in fact seems to be a case of 

 what the earlier Darwinians called correlation, while 

 Mendelian characters may apparently be separated 

 and rejoined in any combination. For example, in 

 breeds of fowls any colour or any type of plumage 

 may be obtained with single comb or with rose comb. 

 In my own experiments on fowls the loose kind of 

 plumage first known in the Silky fowl, which is white, 



