64 BOTANICAL GAZETTE [july 



in experiments on the condition of pollen grains themselves or the 

 effect of diverse pollination. 



Such an apparatus has three fundamental advantages over any other 

 method that the writer has seen described: (i) foreign pollen is abso- 

 lutely eliminated, so far as the writer's experience goes; (2) the cloud 

 of pollen is in violent circulation when it strikes the silks, insuring 

 rather complete pollination, always provided that the pollen and silks 

 are both in good condition; (3) it is a relatively "fool-proof" method, 

 so that pollination can be allotted among unskilled assistants. 



Certain disadvantages may be considered, (i) Expense. — The 

 apparatus can be made up for about 15 cents, and the number of pol- 

 linators need not be great. With a given "load" of pollen 4 or more ears 

 may be pollinated. Repeated loadings may be made as long as pollen 

 from a given tassel is desired. The pollinator is then opened, easily 

 washed in 95 per cent alcohol, wiped out with cotton, and dried within 

 20 minutes, provided there is standing alcohol in none of the parts. 

 The writer usually used about 20 pollinators and then washed them 

 all. (2) Breakage. — This is not a problem provided the bent end at 

 A (fig. i) is not long enough to strike the side of the bulb when the 

 stopper is forced in. (3) Clogging.- — If the bend at B (fig. i) is a clean 

 one, even fragments of tassels contained in the pollen load will pass 

 through readily. This also will depend on the bore of the thistle tube, 

 but the writer encountered practically no difficulties of this sort. (4) 

 Loading. — This is the only aggravating feature of the method. It is 

 not a problem provided the operator can afford to sacrifice the tassel, 

 as the writer usually did. The severed tassel is then shaken within 

 the bag, from which pollen is readily poured into the pollinator. Fre- 

 quently, however, it is desirable to save the tassel. In that case the 

 operator may pull the bag off the tassel and replace after loading. 

 This obviously endangers a wholesale loss of pollen and an exposure of 

 the tassel for a moment. A much better method is merely to loosen 

 the string around the tassel-bag and load the pollinator from one corner 

 of the bag's mouth. This method was employed with considerable 

 success, but it is rather awkward at best and impossible for 12-foot 

 corn. A much more clean-cut method would be to save pollen (rather 

 than tassels) in dry phials, but this multiplies apparatus. With all 

 the drawbacks of loading, however, even an unskilled operator finds 

 little difficulty in using this corn-pollinator. — Merle C. Coulter, 

 University of Chicago. 



