Studies of Teratological Phenomena. 67 



culture, the plants stood close together, or, says de Vries (M. T. 2: 

 p. 516) "I should probably have succeeded in inducing the anomaly in 

 every one of them." 



No sharp limit, according to deVries can be drawn between the 

 normals (atavists) and the fasciated individuals, and he again uses the 

 Crepis race to support his statement. From an isolated group of 

 3 fasciated plants of this race, seed was saved from the one most 

 abnormal and 150 progeny raised under the most favorable conditions. 

 The following results were obtained: 



Stems without fasciation 33 



„ slightly fasciated at top .... 9 



„ fasciated along whole length . . . 108 



Total 150 



or, altogether, about 80 per cent were fasciated. The breadths of the 

 108 fasciated stems were tabulated by classes and a curve plotted, 

 indicating the group of the 33 normals (atavists). Transitions between 

 normals and fasciated individuals occurred, but are said to have been 

 relatively rare. Two pure types were produced then, as shown by the 

 two peaks of the curve. Practically the same results were secured in 

 all the numerous fasciated races with which de Vries experimented, 

 and even the cockscomb, Celosia cristata, belongs to this category of 

 eversporting hereditary varieties, although in its case, "complete atavists 

 are very rare". (M. T. 2: p. 519.) De Vries (see 1906, p. 401, also 

 M. T. 2: pp. 525 — 526) summarizes his conclusions regarding fasciated 

 eversporting varieties as follows: (Nos. 7 and 8 are a free translation). 



1. "Races always consist of fasciated individuals and atavists" 

 (normals). 



2. "The proportion of the former varies greatly, often amounting 

 to only 40 ^/o or less, but not infrequently to more (Geranium 

 and Crepis with 65% and 85°/o; Celosia cristafa).'' 



3. "The fasciated individuals are connected by transitional forms, 

 which are, however, rare; and the statistical curves representing 

 them have therefore 2 apices." 



4. "These proportions are to a large extent dependent on external 

 conditions of life, which can transform atavists into fasciated 

 plants and vice versa. This transformation obviously takes 

 place during the plastic period in youth, before the character in 

 question is actually developed." 



5* 



