Page:Popular Science Monthly Volume 67.djvu/157

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151
THE MUTATIONS OF LYCOPERSICUM.

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 mutation 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.[1] 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 discussions. 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 published in seed growers' catalogues. During that time also at least two new specific plant forms have suddenly originated by mutation from the common species,[2] Lycopersicum. esculentum, 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.


  1. '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 Experiments,' 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.
  2. 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.