! 9 : 5 ] ROSE— DEL A Y ED GERM IN A TION 4 2 7 



lined with sharp, close-set steel points against which the seeds are 

 thrown and scratched as the cylinder revolves. 



Mention should be made here also of an apparatus invented 

 by Kuhle (19) for scraping the rough outer covering from sugar 

 beet "seed." Very satisfactory results have been obtained by its 

 use, since "seeds" so treated absorb water better than untreated 

 ones, and germinate more rapidly; they also give a better total 

 germination, on account of the removal of fungus-infected mate- 

 rial from the outside of the "seed," especially if this removal is 

 followed by treatment with some fungicide. 



With any one of the machines here described except the last, 

 which serves a slightly different purpose, it has been found difficult 

 to treat every seed that passes through and, at the same time, to 

 avoid serious cracking of the coat or bruising of the entire seed 

 (Glockentoeger 11 ). 



It is believed that these difficulties have been avoided in a 

 machine devised and in use during the winter of 1912-1913 at the 

 Hull Botanical Laboratory of the University of Chicago. This 

 machine consists of a direct pressure blower, furnished by the 

 Connersville Blower Co., to which is attached an apparatus through 

 which seeds can be fed and blown against the points of a bank of 

 needles. In experiments conducted with this machine, the blower 

 was driven by a two horse-power motor and gave pressures as high 

 as 2 . 5 pounds to the square inch. The needles used were of three 

 sizes, nos. 4 and n sewing needles and no. 4 darning needles, made 

 up into three different cylindrical bunches or banks, each bank of 

 course consisting of only one size of needles. The needles were 

 held together by solder at the eye end and by wire or a ferrule one- 

 half to two-thirds of the distance from the eye to the point. 



In the cut here shown (fig. 1) the needles are about half an 

 inch from the end of the air tube. In practice a screen cap is 

 placed over the needles and the tube as a covering for a glass jar 

 beneath, into which the seeds fall. To use the apparatus, valve 

 e is closed and valve b is opened; seeds are poured into compart- 

 ment c; valve b is closed and the blower started; valve e is then 

 opened wide enough to let the seeds out, but not so wide that they 

 interfere with each other as they strike the needle points. It is 



