534 Cannon : Studies in Plant Hybrids : 



coupled together in the hybrid organism, not being capable of sep- 

 arating from each other — correlations are not unknown among 

 hybrids. The idea suggests itself that the case might be very dif- 

 ferent if the number of the chromosomes in relation to that of the 

 characters were greater than in the pea ; the chance association and 

 distribution of chromosomes representing portions of characters 

 might not bring about so evident a distribution of characters in 

 the hybrid generations, the Mendelian reversions. May it not be 

 possible then that fortune favored Mendel when he selected for his 

 experimentation plants which had so small a number of chro- 

 mosomes ? * 



New York Botanical Garden. 



List of the More Important Recent Works on Plant Hybrids 



Abbado, M. L'ibridismo nei vegetali. Nuovo Giorn. Bot. Ital. II. 5 : 76, 265. 1898. 



Ames, 0. (i) Lobelia inflatay^cardinalis. Rhodora, 3 : 296. 1901 ; (2) Repro- 

 duction in relation to problems in hybridization. Am. Gard. 22 : 130. 1901. 



Andrews, A. L. A natural hybrid between Ilabenaria lacoa and H. psychodes. 

 Rhodora, 3 : 245. 190 1. 



Arcangeli, G. (i) Sopra alcuni Norcissiis. Bull. Soc. Bot. Ital. 2: 480. 1893; 

 (2) Sopra varie mostruosita dell' Ajax odorus Car., e della sua probabile origene. 

 Bull. Soc. Bot. Ital. 2 : 290. 1893. 



Bailey, L. H. (i) Crosses and crossing of plants. Gard. and For. 5: 2. 1892. 

 (Reprinted in) Gard. Chron. HI. 11 : 235, 256, 298. 1892 ; (2) Cross-breeding 

 and hybridizing. (Rural Library, v. I, no. 6. Ap) 1892; (3) Fruit items. 

 Am. Gard. 14: 500. 1893; (4) Hybridisation in the United States. Jour. Roy. 

 Hort. Soc. 24: 209. 1900 ; (5) Plant-breeding. New York, 1895; (6) The 

 hybridity corollary. Bot. Gaz. 22 : 460. 1896. 



Barron, L. (i) The hybrid origin of roses. Am. Gard. 22: 5. 1901 ; (2) The 

 varying quality of adaptability in hybrid types. Am. Gard. 24 : 200. 1903. 



Bateson, W. (i) Hybridisation and cross-breeding as a method of scientific investi- 

 gation. Jour. Roy. Hort. Soc. 24: 59. 1900; (2) Mendel's principles of he- 

 redity. A defense. With a translation of Mendel's original papers on hybridisa- 

 tion. Cambridge, 1902; (3) Note on the resolution of compound characters by 

 cross-breeding. Proc. Cambridge Phil. Soc. 12 : 5°- I903- 



Bateson, W., & Saunders, E. R. Experimental studies in the physiology of heredity. 

 Rep. Evolution Committee Roy. Soc. Report I. 1902. 



*The data at hand showing the number of chromosomes in the somatic cells of 

 Mendelian hybrids are unfortunately not complete. According to Wilson (The Cell, 

 206), in wheat there are 16 chromosomes, and in cattle and rats the number is probably 

 the same ; the mouse has 24 chromosomes ; according to the present study the pea has 

 14. On the other hand, there are 56 chromosomes in the somatic nuclei of hybrid 

 cotton, but the nature of the variations in the cotton, whether or not Mendelian, has 

 not, I believe, been determined. 



