Studies of Teratological Phenomena. 99 



Table D. 

 Effect of environment on the expression of the factor A. 



When the text photographs were taken (Fig. 15), the plants were 

 6 months old, having passed 2 months in the 15*2 cm. pots. In the 

 course of these two months many died, and the remainder had bloomed 

 and matured seed. Many of their leaves were yellow and the bottom 

 four to seven leaves had fallen. Table D gives their pedigree, the 

 number of survivors to each pot, their height and character. The flowers 

 were as large and as unaffected as though the cultures had been given 

 the best care. The normal flowers were in all respects similar to those 

 of field -grown plants. The leaves were reduced to a fourth of their 

 normal area, but as shown by the table, their number remained unchanged. 

 The main plant stems were very small, but flattening was as charac- 

 teristically expressed, though in 'baby-ribbon' dimensions, as that of 

 field plants. 



While other characters such as leaf size and plant size are 

 modified in expression by adverse conditions this does not seem to be 

 true of fasciation as it appears in Nicotiana, except through its relation 

 to other characters, such as size of stem. Not one single individual 

 of the whole 61 surviving abnormals but what could very easily be 



*) Stem so small in diameter that inflorescence fasciation would be difficult to 

 determine through casual observation. 



7* 



