November 29, 1901.] 



SCIENCE. 



841 



VARIETAL MUTATION IN THE TOMATO. 



The following remarks refer to the orig- 

 ination by mutation * of a strongly marked 

 and distinct variety of tomato from seed of 

 an old and well-known variety, under or- 

 dinary cultivation in an isolated garden 

 plot ; and to the subsequent duplication of 

 that case of mutation upon the same ground 

 and under the same conditions of cultiva- 

 tion, but in plants produced from other 

 seed of that old variety, which was grown 

 in a different and distant region. The mu- 

 tation in these two cases is remarkable in 

 that it was uniformly manifested in every 

 plant of each of the two crops in which it 

 occurred ; that it produced plants which 

 were widely different from the parent 

 plants ; that the second case was an exact 

 repetition of the first, and that it occurred 

 in both cases under circumstances that pre- 

 clude the probability that it was the result 

 of cross- fertilization. 



My observations in these cases were made 

 in connection with amateur gardening upon 

 my house-lot in Washington, a statement 

 of the results of which follows in narrative 

 form. I chose the Acme variety of tomato 

 for cultivation because of its long-known 

 excellence, and the cases referred to oc- 

 curred unexpectedly in the variety thus 

 chosen. In the spring of 1898 I purchased 

 a dozen young plants which had been pro- 

 duced from seed by a gardener in the vicin- 

 ity of Washington, and transplanted them 

 in my garden plot. As the plants matured 

 and fruited they showed all the recognized 

 varietal characteristics of Acme, a descrip- 

 tion of which is herewith given for the pur- 

 pose of comparing it with other varieties 

 presently to be mentioned. The plants 

 were large and diffuse, the color of the 

 foliage being a medium shade of green ; 



* In this article I use the term ' mutation ' in the 

 phylogenetie sense that has been given to it by Pro- 

 fessor Hugo de Vries in his exhaustive work, 'Die Mu- 

 tationstheorie, ' Leipzig, 1901. 



haulms slender, somewhat numerous, some 

 of them reaching a length of more than 

 six feet ; the petiole-midrib long and slen- 

 der ; leaflets moderately narrow, distant, 

 petiolulate and only slightly rugose ; fruit 

 depressed-globular in shape, with an occa- 

 sional tendency to become transversely 

 oval, uniformly ripened, fleshy and well 

 flavored ; and in ripening the change from 

 the chlorophyl-green to crimson, passing 

 through more or less of yellow. 



I selected seeds from one each of the 

 earliest and most characteristic fruits of 

 several vigorous plants of this crop of 

 1898, and made a mixed packet of them. 

 These seeds I planted in 1899, expecting to 

 produce true Acme plants, because of my 

 care in selecting and preserving the seeds, 

 because of the comparative stability of that 

 variety, and because no other tomato plants 

 were grown with them,''or in their neigh- 

 borhood, from which cross- fertilization 

 might have occurred. To my surprise, 

 however, all the plants which ^grew from 

 these seeds were distinctly different fx*om 

 the parent plants of the'year before, both 

 as to habitus and as to fruit, and all were 

 uniform in their new characteristics. They 

 were sturdy and compact plants with foliage 

 of a deeper green than that of the parent 

 plants ; haulms few and strong, the more 

 vigorous reaching a length of about four 

 and a half feet, or an average of about two- 

 thirds the length of the parent plants; 

 petiole- mid rib short and strong ; leaflets 

 moderately broad, not distant, sessile or 

 nearly so, and strongly rugose ; fruit simi- 

 lar to that of the parent plant in size, shape 

 and consistence, but more delicate in color, 

 which changes from the chlorophyl green 

 to cherry-red or light crimson through a 

 neutral or flesh color, a yellow tint st^ldom 

 appearing. It is also singularly free from 

 the pronounced tomato flavor of the com- 

 mon kinds. The seeds which I saved from 

 this new variety were accidently destroyed 



