IV.] EVOLUTION IN BEANS. 131 



a fibrous annual root.* Here is a new form which 

 surely ought to satisfy any person who demands the di- 

 rect origination of a new species as a proof of evolution. 

 There are other curiosities amongst the beans. Gar- 

 deners know two well-marked types or races of the Lima 

 bean, the Sieva type and the Large Lima type. There 

 are good and valid botanical distinctions between the 

 two, which were amply recognized by Linnaeus, who, 

 supposing that one came from Bengal and the other from 

 Africa, made species of them. The smaller, or what we 

 now know as the Sieva type, he called Phaseolus lunatus; 

 the other he called P. inamcenus. The term Lima bean, 

 which all agree in associating with onr Phaseotus lunatus, 

 should properly be applied, therefore, to the Sieva type. 

 For a century these species of Linnaeus were generally 

 considered to be good, — that is, distinct and valid. It is 

 now pretty well established that both these beans came 

 from Brazil. Only one of them is known in a truly wild 

 state, and the suspicion is so strong, therefore, that the 

 other sprung off from it under cultivation, that the two 

 types are now united as one species. Still a third well- 

 marked type, differing in shape and texture of leaflets, 

 and characters of pods and seeds, has now originated 

 from the Large Lima type; this is the Potato Lima type. 

 It shotild also be said that Macfadyen, in his flora of 

 Jamaica, made four new species out of the Lima type of 

 beans. Here, then, are three groups of beans, each as 

 distinct from the others and from its ancestors as ac- 

 cepted species of Phaseolus are from each other, yet, 

 because of their origin under domestication, they are 

 debarred specific distinction. Now, a most curious thing 

 about these dwarf Lima beans, which have appeared so 



*For au account of these beans, see Cornell Bulletin 87. 



