246 Plant-Breeding 



many starting-points as possible, to lessen the risk of 

 failure. Whilst it requires nice judgment to choose 

 those plants which possess the most important and the 

 most transmissible combination of characters, the great- 

 est skill is nevertheless required to carry forward a correct 

 system of selection. 



14. Even when the desired variety is obtained, it must 

 be kept up to the standard by constant attention to 

 selection. That is, there is no real stability in the forms 

 of life. So long as the conditions of existence vary, 

 so long will the plants make the effort to adapt themselves 

 to the changes. No two seasons are alike ; and no two 

 fields, or even parts of fields, are alike ; and there are no 

 two cultivators who give exactly the same and equal at- 

 tention to tillage, fertilizing, and the other treatment of 

 plants. All forms or varieties, therefore, tend to "run 

 out" by variation or gradual evolution into other forms; 

 but because we keep the same name for all the succeeding 

 generations, we fancy that we still have the same variety. 



" In 1887 I found a single tomato plant in my garden 

 in Michigan, that had several points of superiority over 

 any other of the one hundred and seventy varieties I 

 was then growing. It came from a packet of German 

 seed of an inferior variety. The tomato was very solid, 

 an unusually long keeper, productive, and attractive in 

 size and appearance. The variation was so promising 

 that I named it in a sketch of tomatoes that I published 

 that year, calling it the Ignotum (that is, unknown), 

 to indicate that the origin of it was no merit of my own. I 

 sent seeds to a few friends for testing. I sowed the seeds 

 for about five hundred plants in 1888 in an isolated patch 



