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 83, (page 353) Ohio Experiment Station, as 
follows: “Prof. Arthur has recently shown 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 the 
German’s claim, yet I determind to investigate for myself. 
I carried on the 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, 3000 burs; 2751 grew two plants to the bur. 
Of the remaining 249 burs some 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 only object was to de- 
termine whether the two seeds could 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 cockleburs 
grow abundantly. It was passed through a % inch-mesh wire sieve, 
and carefully searched over with the aid of a glass. This 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? 
