114 THE GRAPE IN KANSAS. 



CLASS 2 concluded. 



3 Little Blue. *3 Paragon. 3 Skull's No. 3. 



3 Livingston. *3 Perkins. 3 Standard. 



3 Marie Louise. 3 Rockwood. 4 Triumph. 



*3 Mills. 3 Rogers' s No. 13. *2 Ulster. 



* 3 Missouri Reisling. 3 Rogers' s No. 24. * 3 Victoria. 



Norfolk. 3 Rogers' s No. 32. 3 Wheaton. 



3 Olita. *3 Rommel. 3 Witt. 



3 Paradox. 



CLASS 3. Clusters unmarketable. 



The first two classes include the great majority of commercially profitable 

 varieties. Since the varieties in classes 3 and 4 will not fruit well when standing 

 alone, they should be planted beside other grapes which bloom at the eame time. 

 As a guide to the blooming season, figures 1, 2, 3, 4 and 5 have been placed oppo- 

 site varieties in bloom at approximately the same date. Grapes belonging to the 

 vulpina ( riparia ) species, river grapes, of which Clinton and Marion are examples, 

 are first in bloom ; then the cestivalis species, summer grapes, of Mills and Ulster 

 type; later, the fox grapes, or labruscas. Concord, Isabella, etc.; and last, the 

 post oak grapes (Vitis lincecumii), and other species whose natural home is 

 the Southwest. There is, of course, no marked line of separation between the 

 groups given, many of the earlier varieties extending their period of bloom nearly 

 as long as other varieties in the group following, so that early bloomers might be 

 fertilized to some extent by a later class. 



The physiological explanation for this condition of self-sterility has not been 

 absolutely determined, but the failure is probably due to a lack of affinity be- 

 tween the pollen and pistils of the same variety. It is a phenomenon very similar 

 to the failure of mules and other hybrids to breed, and probably due to the same 

 causes; for most, if not all, the varieties found to be sterile or nearly so are 

 hybrids between different botanical species of grapes. 



All of the perfect-fruiting varieties were found to have long stamens; and all 

 varieties which had short stamens, as well as a few which had long stamens, gave 

 imperfect fruit or none at all. "The fact that a variety has short stamens may 

 be taken as pretty sure evidence that it is self-sterile"; but, as stated, not all 

 varieties with long stamens are self-fertile. 



