On " The Saltwater Selection " Method of Seeds. 



BY 



T. Yokoi. .Vugal-iis/ii. 

 Pri^ft ssor of . i^riai/liirc. 



A method of selecting seeds by specific gravity has been long in 

 use in Japan and China. In China a famous author*^'^ already speaks 

 of the so-called "water selection" method. It is stated that those 

 seeds tliat float on water are of a poor quality and should be rejected. 

 In Japan, an unknown author of an unknown date but who is sup- 

 posed to have written in the period of Genroku (1688 — 1703) mentions 

 the same method of selection and even goes into the details of the 

 operation with special reference to rice seed and states furthermore 

 that it is the method said to have been followed from olden times. 

 Thus inasmuch as its details were known, it may fairly be concluded 

 that the method was of a much remoter origin. Indeed, it is not 

 without reason to suppose that when Roman farmers steeped their 

 seeds in various solutions and extracts, and when farmers of Asiatic 

 countries"' steeped their rice seeds in water, they threw off the 

 light and immature seeds floating on the surface of the liquid. But 

 this kind of selection which is without an aim, is called by Darwin 

 " unconscious selection" and differs from those methods of selection 

 which are now so widely in use in civilized countries, — systematic 

 selection. 



Whether the quality of seeds has any relation with tlicir specific 

 gravity or not is a question which has been much discussed of late. 



(1) Xung-ching-ts"iuen-shu, first published in 1639. 



(2) An erroneous but unfortunately often cjuoted statement of S. Julien as to a ceremony 

 said to be established by the Emperor Chin-nung in which the sowing of five Idnds of grains 

 is the chief observance must be here pointed out. This statement even led De Candolle to 

 conclude that rice is probably the native of China. The ceremony established by the 

 Emperor was certainly not of this kind. Indeed in the so-called five grains (hemp[?]), 

 common and glutinous millets, barley and soy bean) the sownig of which was established as a 

 ceremony in a much later time than Chin-nung, rice was not included. According to a 

 rehablc Chinese authority, rice was excluded from the " five grains " in remote ages and 

 only in later periods it was included, because men of hterature in ancient China mostly lived 

 in the northern provinces where rice was then not cultivated. In my opinion, rice is probably 

 not incligenous to China. 



