Mar., 1901] Masterman — Cocklebur Seeds. 69 



THE SPROUTING OF COCKLEBUR SEEDS. 

 E. E. Masterman. 



In July, 1896, Dr. E. W, Claypole, then of Buchtel College, Akron, 

 Ohio, asked me how general was the belief that one seed of the coc- 

 klebur grew one year and the other the next year or later. Inquiry 

 of about twenty of the older residents resulted in procuring no in- 

 formation touching the same. In 1897, I was told by a German 

 farmer that one seed only grew one year and the other later, never 

 both at the same time. A short time after I noticed the statement 

 of A. D Selby in Bulletin S3, (page 353) Ohio Experiment Station, as 

 follows: "Prof. Arthur has recently sftown that only one of these 

 seeds can be caused to germinate the first year, the other always re- 

 maining until the second year." This was a confirmation of tlie 

 German's claim, yet I determind to investigate for myself. 



I carried on tlie experiment for three years with the following 

 results : 



In 1898, I planted 1000 burs; 917 grew two plants to the bur. 

 In 1899, I planted 1000 burs; 921 grew two plants to the bur. 

 In 1900, I planted 1000 burs; 913 grew two plants to the bur. 

 Total three years, 8000 burs; 2751 grew two plants to the bur. 



Of the remaining 249 burs sonie grew one plant, some none ; some 

 had one, some had two apparently sound seeds. I regret that no 

 further notice was taken of these seeds. The on/,;/ object was to de- 

 termine whether the two seeds cow/cZ be made to grow at the same 

 time. An account of the work was sent to Professor Selby, asking 

 whether further experiment was necessary; he replied that he 

 thought not. 



Perhaps it should be added that I selected only apparently sound 

 burs; soil was taken from a field near a creek where cocklebui's 

 grow abundantly. It was passed through a }<£ inch-mesh wire sieve, 

 and carefully searched over with the aid of a glass. Tliis soil was 

 taken to a distant part of the farm ; in it the seeds were planted and 

 nature did the rest. 



I also made observations as follows: I searched among speci- 

 mens growing for a mile along a creek, for two plants growing 

 together and not nearer than five inches to any other plant. Of 

 the 1500 specimens examined each year for three years, two plants 

 always grew from one bur. 



Why have I obtained such opposite results as compared with 

 Professor Arthur's? Can it be referred to locality, soil, or some 

 other more favorable conditions? 



L I B R A R Y ! ay] 



