THE TYPES OF MULBERRIES 161 



other use thaii the feeding of silk worms, and the 

 botanical perplexities of the genus Morus, to which 

 lln-sc trees belong. 



For two or three centuries the earth has been 

 searched for new forms of mulberry trees for the feed- 

 ing of the silk worm. All the best types have been 

 found to be forms of the white mulberry (Morns alba] 

 of China, or types which are evidently direct offshoots 

 of it. This type of mulberry trees produces fruit of 

 inferior quality, and little effort has been made to 

 develop fruit -bearing varieties of it. The fruit- 

 bearing mulberry of history is another species, the 

 black mulberry (Morus nigra) , probably a native of 

 Persia and adjacent regions. But there has been very 

 little desire for the introduction of a fruit -bearing mul- 

 berry in this countrj r , so that the black mulberry is 

 little known here, although horticultural writers have 

 generally referred any valuable fruit -bearing mulberry 

 which has chanced to appear in this country to Morus 

 nifjrn, because this is the species described in the Euro- 

 pean fruit-books. A third important factor in the 

 evolution of American mulberries is the re -introduction 

 in recent years of the Morus Tatar ica, now generally 

 known in this country as the Russian mulberry, and 

 which is really only an outlying form of the white 

 mulberry. 



A fourth important factor is the native red or 

 purple mulberry (Morus rubra, Figs. 20, 21), and to 

 this we need to give special attention in this explora- 

 tion of the evolution of our native fruits. The species 

 is greatly variable, and it grows naturally from west- 

 ern New England and Long Island to Florida and 

 Kansas and Texas. It is mentioned by very many of 



