Acclimatization. 95 



to me of the direct and prompt action of climate on a 

 plant, and Wallace regards this transformation as a 

 result of that "reversion to mediocrity' which invariably 

 occurs and is more especially marked in the case of vari- 

 eties zvhich have been rapidly produced by artificial se- 

 lection. It may be considered as a partial reversion to the 

 wild or unimproved stock. 



Let us now see what Metzger says. He is deaHng 

 with a white broad-seeded American Maize, the Taras- 

 cora Corn from St. Louis. 



''We cultivated this form^ and got stems 12 feet 

 high in the first years and only a few ripe seeds of which 

 the lowest on the cob were like the original form whilst 

 the upper ones appeared to lack the depressions and to 

 show features like those of the European Maize. 



"We sowed the seeds from these next year and ob- 

 tained plants from 9 to 10 feet -high whose seeds ripened 

 earlier. The seeds were noticeably larger than in the 

 previous year, the depression on the surface had already 

 disappeared and the beautiful white color appeared darker 

 and dirtier. Some seeds were yellow; and their round 

 form was just like that of our own maize and betrayed 

 no signs whatever of the characters of the form from 

 which they had sprung. In the third year of the culti- 

 vation all the characters of the American form had dis- 

 appeared and the American maize had been transformed 

 into subspecies 5 form B.^ We obtained another lot 

 of the seed of this same varietv which in the third vear 

 approached the same subspecies 5, B and exactly resem- 

 bled it after six years of cultivation. This maize is now 



^ From the description the variety must have belonged to the 

 Dent corns. ^ 



^ Large White European Maize. Zca praecox L., p. 213. 



