LUTHER BURBANK 



The instinct of migration comes to the martins 

 in September, not in August, or at least not in 

 early August. The habit of migration is no more 

 determined by any conscious judgment of the bird 

 than is the habit of spring growth determined by 

 a conscious judgment of the rhubarb. 



The force of untold generations of ancestors 

 impelled the martins to remain where they were, 

 even though starvation was the penalty. 



Wings they had, with which they might have 

 sought and found a new environment where food 

 was plentiful; but they were powerless to use 

 the wings at this particular season, because the 

 particular week had not arrived at which the 

 hereditary clockwork of their organisms would 

 strike the hour for migration. Taken by and 

 large, it is better for the race of martins that 

 they should not ntiigrate until September; this 

 fact had been established through the test of 

 thousands of generations, and the result was 

 registered indelibly in the organism of every bird. 

 Were it possible to destroy the racial tradition 

 in the interests of any single generation, the life- 

 habits of the species would become so variable 

 and desultory that racial continuity would be 

 endangered. 



So the individuals of a generation throughout 

 a large region were sacrificed to a racial instinct 



[188] 



