76 White. 



fasciation. Mechanical injury, sudden arrest of growth, insect and 

 fungous depredations, injury due to climatic factors (frosts, increased 

 humidity), poor seed associated with richly fertilized soils and intensive 

 cultivation are probably only a very few of these numerous environ- 

 mental conditions. But the internal factor or factors are just as 

 important as the external ones, as shown by the results obtained in 

 attempting to produce this phenomenon experimentally. All plants, even 

 of the same species or of even closer taxonomic affinity, when subjected 

 to apparently identical environmental conditions do not respond in the 

 same degree or in the same manner. This is amply illustrated by the 

 results obtained by Hus, Reed and others. Cucurhito pepo seedUngs 

 did not become fasciated with Reed's methods, but fasciated plants of 

 this species are recorded by de Vries. Fasciated races never bred 

 true with de Vries, although he tested out many fasciated individuals 

 belonging to numerous diverse species, by growing large numbers of 

 their progeny. Even the old established horticultural varieties of 

 cockscomb proved to be inconstant in his cultures, as far as the 

 character fasciation was concerned. On the other hand, Goebel found 

 the cockscomb to be absolutely constant in his cultures even when they 

 were grown in sterile sand. Fasciation is also known to be an absolutely 

 constant character in several races of plants, as the hundreds of 

 individuals comprising several generations that have been raised under 

 controlled conditions, testify. Normal strains of these same fasciated 

 races are also common, and in the case of peas, have bred true to 

 absence of fasciation for at least a quarter of a century. Are we to 

 believe that the character fasciation is latent in these normal strains, 

 or are the facts more clearly expressed by looking upon it as absent? 

 From the standpoint of genetics, the latter interpretation is by far the 

 more preferable, because it more clearly expresses the facts in the case, 

 as we know them. There are undoubtedly constant hereditary races of 

 fasciated plants, — races, in which every plant derived from the seed 

 of a self -fertilized fasciated parent, is fasciated, if both parent and 

 progenj^ are grown under identical environments. There are also constant 

 normal strains of these same species, which breed true to normalness, 

 when all are grown under the same environment as their fasciated 

 relatives. There are still other races of plants in which fasciated 

 individuals are common and the percentage of these abnormals vary 

 greatly as in the case of the Crepis with which de Vries experimented. 

 Progeny grown from such fasciated races under the same conditions as 



