102 Siiihloi Appcanuicc and Constancy. 



and altogether better than any varieties then known ; it 

 was constant from the first and spread rapidly. 



I shall conclnde this summary with a reference to the 

 new species of Tomatoes which Bailey has recently 

 described.^ He describes the oriii,in of two new forms 

 which he has called Upright and Mikado and which arose 

 in his cultures. They differ from one another and from 

 the parent species by more definite and more numerous 

 characters than many amonsf the older forms which are 

 recognized as good species in the genus Lycopcrsicnni. 

 They arose suddenly as usual and were propagated by 

 seed. 



The observations recorded in this and the two preced- 

 ing sections, which are far from constituting complete 

 lists, show that the origin of varieties and of elementary 

 species both in the garden and in the field is amenable to 

 experimental investigation, for the phenomenon is by no 

 means so rare as is generally believed. The botanist 

 will investigate the indifferent and useless forms with 

 just the same result as the profitable ones, to which alone, 

 of course, the practical man pays attention. The cultures 

 need not be very extensive to aft'ord novelties from time 

 to time, though these must not be expected the first or 

 every year. Once obtained, all that there is to be done 

 is to isolate them as soon as they appear and pollinate 

 them artificially. But it is far more important to go 

 back to their ancestors, partly not to lose the historical 

 evidence, but mainly in order to sow the seeds of these 

 ancestors again and to find out if the novelty will be again 

 produced, and if possible to discover the conditions which 

 determine its appearance. l,^nf(3rtunately there are many 

 plants which do not lend themselves to such experiments, 



* L. H. Bailey^ Survival of the Unlike. 



