recombination of characters derived from different 

 ancestral lines. 



For this early departure from "the narrow 

 path " I have in part atoned in my recent 

 paper on the " Genotypes of Maize," 7 by re- 

 ferring to the vegetatively reproduced potato 

 and paramecium as "clonal varieties," in 

 contradistinction to the self -fertilizing "pure 

 lines " of beans, barley, etc. I might equally 

 well have called them simply " clones," as 

 " clonal varieties " and " clones " should have 

 identical meaning. The word "clone" (Greek 

 K\<I>V, a twig, spray, or slip) was proposed by 

 Webber 8 for "groups of plants that are 

 propagated by the use of any form of vegeta- 

 tive parts, such as bulbs, tubers, cuttings, 

 grafts, buds, etc., and which are simply parts 

 of the same individual seedling." I believe 

 that no violence will be done by extending this 

 term to include animals which are similarly 

 propagated by any asexual method, and I 

 suggest the general adoption of the word 

 " clone " for all groups of individuals having 

 identical genotypic character, 9 and arising by 

 asexual reproduction of any sort, including 

 apogamy (i. e. } so-called " parthenogenesis " 

 unaccompanied by a reduction division). 



For the purposes of my discussion in 1904 

 the distinction between "pure lines" and 

 " clones " was of no consequence, because the 

 particular hereditary principle then under 

 consideration was common to both. The same 

 thing is no doubt true of many of the recent 

 investigations of others, but it is well to re- 



'Amer. Nat., XLV., 234-252, April, 1911. 



8 SCIENCE, XVIII., 501-503, October 16, 1903. 

 For a discussion of the spelling of the word 

 "clone" see SCIENCE, XXIL, 89, July 21, 1905. 



9 This restriction is necessary in order to avoid 

 confusion through the appearance of bud-muta- 

 tions. Such a mutation if propagated vegetatively 

 represents the origin of a new clone. 



