THE MUTATIONS OF LYCOPERSICUM. 151 



THE MUTATIONS OF LYCOPERSICUM. 



By Dr. CHARLES A. WHITE, 



SMITHSONIAN INSTITUTION. 



DURING the years 1901 to 1903 inclusive I published results of 

 my observations and experiments concerning the horticultural 

 variability, atavic reversion or degeneration, and phylogenetic muta- 

 tion of the common cultivated tomato. The reader is referred to 

 those publications for such statements of pertinent facts as may be 

 omitted from this one.* The object of the present article is to give 

 in popular form a concise restatement of my experimental observations 

 upon some remarkable cases of saltatory plant mutation and varietal 

 changes of the tomato fruit, together with figures and additional dis- 

 cussions. Although the cases of plant mutation referred to constitute 

 the leading part of my subject, I will first discuss the origination and 

 and decadent extinction of the improved fruit varieties which have 

 arisen in connection with, and apparently as a result of, horticultural 

 conservation. These discussions are necessary to the making of a 

 clear distinction between fruit variation and plant mutation as I shall 

 have occasion to refer to them. 



The enormous increase in the importance of the tomato as an article 

 of food during the past thirty years has so stimulated its cultivation 

 that very many fruit varieties of fine quality have resulted, figures 

 and descriptions of the more important of which are annually pub- 

 lished in seed growers' catalogues. During that time also at least two 

 new specific plant forms have suddenly originated by mutation from 

 the common species,f Lycopersicum. esculenium, making not less than 

 three species of the cultivated tomato. It is desirable to characterize 

 these species briefly in connection with the discussion of the fruit 

 varieties which they bear. The two new species referred to I have 

 called L. solanopsis and L. latifoliaium, respectively, of course leaving 

 the original name, L. esculentum, with the unmutated, or mother form. 



* ' Varietal Mutation in the Tomato,' Science (n. s.), vol. xiv., pp. 841-844, 

 New York, Nov. 29, 1901. 'The Saltatory Origin of Species,' Bull. Torrey Bot. 

 Club, vol. xxix., pp. 511-522, New York, Aug., 1902. 'My Tomato Experi- 

 ments,' The Independent, vol. liv., pp. 2460-2464, New York, Oct. 16, 1902. 

 'Aggregate Atavic Mutation of the Tomato,' Science (n. s.), vol. xvii., pp. 

 76-78, New York, Jan. 9, 1903. 



f To avoid undue repetition, the terms ' species ' and ' plant forms ' are 

 used interchangeably; and the term ' mutation ' is used in its now accepted sense 

 of sudden origination of species. 



