472 The Journal of Heredity 



the edges and cut into pieces long frame may then be readily opened to 



enough to fasten easily over the ends of inspect or pollinate the flower by simply 



a \\are frame (E). This is formed, as untwisting the upper wire and turning 



seen at (B), by bending a strip of wire back the cloth. 



netting around a test tube and turning Light cardboard may be substituted 



back the ends of the long wires to hold for the wire netting, but is not as good 



the frame together. The frame is now in case of rain. The size of the frame 



cut off and inserted in the muslin tube should be varied, of course, to suit the 



by means of a somewhat larger test case. Where the flowers are small and 



tube (C). A piece of fine copper wire gathered at the end of a stem it is 



at each end completes the whole. (D). better to use a large sac and enclose the 



To use, one end of the cloth is turned whole cluster, 



back over the frame like a cuff (F). It No positive claim is made for origi- 



is then slipped over the flower and the nality as the device is one which might 



cloth fastened about the stem with a occur to anybody and doubtless has 



few twists of wire as at (G). The been used by others. 



Plant Breeding in Minnesota 



More than 300,000 plants a year are handled by the breeders of the Minnesota 

 Agricultural Experiment Station, mostly with the object of increasing yield or 

 hardiness. In alfalfa, the object is to produce better seed-bearing strains. Sugar 

 beets are cros.sed with mangels to produce a good stock beet. Commercial varieties 

 of grape have been carefully studied, some being found to be self -sterile and some 

 self -fertile. In the self -sterile forms, the generative nucleus becomes degenerated, 

 which prevents the further functioning of the pollen grain. This is believed to be 

 the first time that the actual cause of self-sterility in grapes has been determined; 

 obviously no cultural expedients can possibly overcome such a trouble, and the 

 only remedy is the use of proper varieties. It will be recalled that the native Amer- 

 ican grapes, as a class, seem to be practically monoecious in nature. Although 

 bearing vines produce male as well as female flowers, their female flowers are 

 usually incapable of pollination from male flowers on the same vine, and depend on 

 cross-pollination from \dnes that bear exclusively male flowers and — of course — no 

 fruit. Such is the condition among the wild vines; but in the commercial varieties 

 which have been created from them this habit has been modified, until in many 

 cases a bearing vine produces good pollen for its own female flowers, and the planting 

 of distinct male vines is unnecessary. Evidently, however, this habit is not well 

 enough fixed to be wholly dependable, and is better fixed in some varieties than 

 others. The scientific grape grower, then, will ascertain before planting just how 

 the varieties he has picked out will behave when sclf-])ollinatcd, and if they do not 

 take kindly to this artificial means of fecundation, he will plant out enough male 

 vines to insure a crop. Similar work has been done with the plum and strawberry. 

 Statistical studies of the characters of many fruits are being made. 



Why Do Apples Bloom Late? 



The main breeding i)roblem at the Virginia Agricultural Exjjeriment Station is 

 with ai)]jles, and the investigators are making a determined effort to find whether 

 the late blooming attribute is a hereditary quality transmitted by definite discover- 

 able laws. In addition there are genetic studies of color inheritance in lupins, 

 phlox and other ornamentals, and a study of the possible inheritance of disease in 

 the tomato. 



