4 HEREDITY AS ILLUSTRATED BY TRICHOMES. 



Solanum villosum X Solanutn guineiise was produced by Mr. Burbank 

 and is now growing: in his experimental grounds at Santa Rosa, California. 

 Solanum guinense, a native of central west Africa, is a perennial of bushy- 

 habit of growth, and bears black fruit of unpleasant flavor; Solanum villo- 

 sum, from Chile, is an annual, dwarfed and procumbent, and bears clusters 

 of small, hard, and green berries.* The hybrid is a low, bushy perennial, 

 and produces berries agreeable to the taste, the flavor of which recalls that 

 of the low-bush blueberry of the eastern United States. The hybrid has 

 not been known to revert, although its culture, begun in 1897, has been 

 carried to the fifth generation; it, therefore, is an instance of the breeding 

 true of a first cross. 



The material for study of all hybrids procured from Mr. Burbank was 

 either collected by the writer and fixed in the usual manner, or was put up 

 by Dr. G. H. Shull in weak formaldehyde. To both of these gentlemen 

 thanks are due for the preparation of material, and to Mr. Burbank, who 

 so generously gives both his plants and his time for the forwarding of the 

 study of plant hybrids, acknowledgment is especially and gratefully made. 

 Acknowledgment should also be made to the directors of Hopkins Seaside 

 Laboratory, Pacific Grove, California, for the use of a research-room dur- 

 ing the summer of 1907, and to the Carmel Development Company, Carmel- 

 by-the-Sea, California, who provided a laboratory which was used during 

 the summer, 1908. 



*Year Book, Carnegie Institution of Washington, 1907. 



