No. 50G] DAhAVIX AM) MFTATIOX T1IEOUY 



sterile." 22 The last point, however, docs not 

 the claim to this new type of Begonia as a ami 

 the facts which determine its position in this n 

 first, the sudden appearance of the form heai 

 kinds of flowers and, second, the production l> 

 descendants also bearing three kinds of flowers 

 It is very evident that this case troubled Mi 

 for he referred to it a number of times and did 

 Professor Harvey's assertion that "such a case 

 to the theory of natural selection, according 

 changes are not supposed to take place per salt 

 Harvey's further declaration that k4 a few s 

 would overthrow it (natural selection) altogethe 

 Joseph Hooker attempted to explain the matte 

 weaken Professor Harvey's argument againsl 

 trine of natural selection, hut Darwin hims 

 Hooker, saying : 



often changed by saltum. 



About the same time, namely early in 1860, Darwin 

 wrote to Lyell on this subject, saying: 



It seems to me rather strange; he (Harvey) assumes the permanence 

 of monsters, whereas monsters are generally sterile and not often in- 

 heritable. But grant this case, it comes that I have been too cau ious 

 in not admitting great and sudden variations." 



There is an added point of interest about this discus- 

 sion in the fact that it is the earliest record in print of 

 the consideration of saltation or mutation by Mr. Darwm. 



You have doubtless noticed Mr. Darwin's protest 

 against the belief in the occurrence of important changes 

 "per saltum." He uses this expression with disap- 

 proval a number of times and yet his condemnation ot 



-Ibid., 1st ed., Vol. H, p. 166. Also ibid., 2d ed., Vol. II, p. 150. 

 13 "Life and Letters," 1886, Vol. II, P- 274. 



