Studies of Teratological Phenomena. 



81 



slightly flattened. The opinion is expressed that different degrees of 

 fasciation may be inherited. 



One of Emerson's corn families shows an extreme type of fas- 

 ciation, not present in any of the others (Fig. 9). 'From a 1910 family 

 of popcorn that contained both normal and abnormal ears, four fasciated 

 ears were selected and used as parents of 1911 families.' The results 

 obtained were as follows: 



Character of Ears. 



1911 



Ear 1 

 Ear 2 



Ear 3 



Ear 4 



All strongly fasciated. 

 All strongly fasciated. 

 12 more or less fasciated. 

 3 perfectly normal. 



Strongly abnormal, normal and all intergrades 

 making classification impossible. 



From one of the first two families, I examined and collected ears, 

 and found very little variation in the expression of the anomalous 

 character. Another family grown from a fasciated ear gave a proportion 

 of 32 plants with more or less fasciated ears, and 35 plants with 

 apparently normal ears, though some of the latter may have been 

 slightly flattened. The parent of the above family was also crossed 

 with an 8 -rowed dent corn plant. The Fi generation contained 63 

 plants, all producing perfectly normal ears. In other crosses (1912) 

 between fasciated and normal races, the Fi was also perfectly normal. 

 About 25 per cent fasciated plants occurred in some F2 families, while 

 in other crosses even less than 25 per cent were fasciated. Emerson 

 believes soil and climatic conditions to have considerable influence on 

 the expression of fasciation in maize. In some strains, he thinks 

 perhaps two Mendelian factors are involved. The suggestion is also 

 made that 'interaction between a single fifsciation factor' and the 

 diverse characters present in the different strains, may provide just as 

 good an interpretation for the complexities in the results as the postu- 

 lation of more than one factor. 



Induktive Abstammungs- und Vererbungslehre. XVI. 6 



