Januaey 9, 1903.] 



SCIENCE. 



77 



Parish, Louisiana. The father there planted 

 the seed of a choice variety of tomatoes which 

 were obtained from the former family home 

 in New York state, the first crop of fruit from 

 which was perfectly true to seed. He was, 

 however, then informed by a neighbor who 

 had lived in that region many years that, to 

 produce good fruit, seed must be obtained 

 from the North for every year's planting, be- 

 cause all the seed of tomatoes grown in that 

 southern region would produce the small, 

 spherical, inferior fruit, from whatsoever 

 improved variety the seed may have origin- 

 ally come. The neighbor's advice was taken, 

 northern seed was annually procured for fu- 

 ture crops, and the first crop of resulting fruit 

 was in all cases as characteristic of its variety 

 as if the plants had grown in their native 

 northern soil. But the truth- of the reputed 

 atavic mutation was afterward repeatedly 

 demonstrated on the Bayou Teche plantation 

 under Miss Starr's observation by growing 

 and maturing plants from seed of fruit which 

 was grown there from northern seed. The 

 permanence of the atavic mutation was also 

 demonstrated by hereditary constancy in suc- 

 cessive generations; and its completeness was 

 shown in every plant of the second southern 

 crop from northern seed, as well as in all sub- 

 sequent crops. 



These two cases are stated so clearly by 

 my correspondents, and agree with each other 

 so closely as to the main facts, that one can- 

 not doubt their genuineness. One also can- 

 not doubt that many other similar cases are 

 constantly occurring in various regions, the 

 details of which are not publicly reported. 

 This article is vrritten in hope of eliciting 

 such information of similar cases as shall 

 materially aid further investigations. Re- 

 ports of such cases should embrace detailed 

 statements concerning attendant horticultural 

 and local climatic and other conditions, and 

 mention of the several varieties whose muta- 

 tions are observed. The interest attending 

 a consideration of the varieties involved in 

 mutations may be illustrated by the cases of 

 phylogenetic mutation before referred to. In 

 those cases the mutative act was accompanied 

 by the production of one specific form from, 



another, and it is desirable to know if, in cases 

 of atavic mutation like those just mentioned, 

 the reversion may be direct from a specific 

 form that has thus arisen. For example, in 

 those phylogenetic cases the mutation was 

 from Lycopersicum esculentum, to L. solcm- 

 opsis, and the discovery of a case of atavic 

 mutation involving a retrograde change from 

 the latter species to the former without re- 

 tracing the varietal steps of the genetic line 

 would, therefore, be of interest in connection 

 with the theory that such mutations originate 

 in molecular changes. In the case reported 

 by Mr. Browne mutation was only varietal 

 or intraspecific in its scope. That is, it was 

 within the species L. esculentum because both 

 the Trophy and Cherry varieties belong to 

 that species, and I do not now know whether 

 such atavic mutation as occurred in the cases 

 here mentioned has ever been interspecific in 

 scope, that is, from one species to another. 

 Cases of atavic reversion of fine varieties 

 of tomatoes are well knovm to gardeners, but 

 those are generally cases of varietal degenera- 

 tion complicated by hybridization. In the 

 cases reported by Mr. Brovme and Miss Starr, 

 respectively, mutation seems to have been sud- 

 den, complete and aggregate for the whole 

 crop. It is, therefore, improbable that it was 

 a result of hybridization in either case. If 

 those northern seeds had been sown in their 

 native soil one cannot doubt that their prog- 

 eny would have been true to seed in suc- 

 cessive generations. Therefore, one also can 

 not doubt that the exciting cause of those 

 atavic mutations was local for the regions in 

 which they respectively occurred. In those 

 cases of phylogenetic mutation which have 

 been referred to, the initial step evidently oc- 

 curred in the seed of the fruit of the Acme 

 variety which I had myself grown from au- 

 thentic Acme seed. So also in the cases of 

 atavic mutation herein mentioned the initial 

 step seems certainly to have occurred, not in 

 the somatic cells of either root, stem, leaves 

 or pericarp of the first crop of plants grown 

 in southern soil from northern seed, but only 

 in the germ cells of those plants. In subse- 

 quent generations, however, mutation extended 

 to the pericarp, that is, to the fruit; but the 



