i864— J 869] IJUD-VARIATION 275 



To T. Rivers. 1 Letter 195 



Down, Dec. 23rd [1866?]. 

 I do not know whether you will forgive a stranger ad- 

 dressing you. My name may possibly be known to you. I 

 am now writing a bouk on the variation of animals and plants 

 under domestication ; and there is one little piece of informa- 

 tion which it is more likely that you could give me than 

 any man in the world, if you can spare half an hour from 

 your professional labours, and are inclined to be so kind. 

 I am collecting all accounts of what some call " sports," that 

 is, of what I shall call " bud-variations," i.e. a moss-rose 

 suddenly appearing on a Provence rose — a nectarine on a 

 peach, etc. Now, what I want to know, and which is not 

 likely to be recorded in print, is whether very slight differences, 

 too slight to be worth propagating, thus appear suddenly by 

 buds. As every one knows, in raising seedlings you may 

 have every gradation from individuals identical with the 

 parent, to slight varieties, to strongly marked varieties. Now, 

 does this occur with buds or do only rather strongly marked 

 varieties thus appear at rare intervals of time by buds? 2 I 

 should be most grateful for information. I may add that if 

 you have observed in your enormous experience any remark- 

 able " bud-variations," and could spare time to inform me, and 

 allow me to quote them on your authority, it would be the 

 greatest favour. I feel sure that these " bud-variations " are 

 most interesting to any one endeavouring to make out what 

 little can be made out on the obscure subject of variation. 



To T. Rivers. Letter 196 



Down, Jan. 7U1 [1867?]. 



I thank you much for your letter and the parcel of 

 shoots. The case of the yellow plum is a treasure, and 

 is now safely recorded on your authority in its proper 

 place, in contrast with A. Knight's case of the yellow 



1 The late Mr. Rivers, of Sawbridgeworth, was an eminent horticul- 

 turist and writer on horticulture. For another letter of Mr. Darwin's to 

 him see Life and Letters, III., p. 57. 



2 Mr. Rivers could not give a decided answer, but he did not 

 remember to have seen slight bud-variations. The question is discussed 

 in Variation under Domestication, Ed. 11., Vol. I., p. 443. 



