Birds as Destroyers and Distributers of Weed Seeds. 73 



the Department the probability that the English sparrow was 

 responsible for the occurrence of crab-grass in lawns and golf links 

 sown with pure seed of the finest brand. Much complaint was 

 received from the buyers of lawn-grass seed because, after the seed 

 was planted and the turf well-established, crab-grass appeared in 

 it, often so thickly as to necessitate plowing under the whole lawn. 

 Two sparrows were fed with 100 of the seeds. Instead of manipu- 

 lating them as they did the seeds of millet and pigeon-grass they 

 swallowed them whole, without removing any of the ensheathing 

 glumes. Gravel was furnished so that the grinding power of the 

 birds' gizzards might be facilitated, and after several hours six 

 droppings were collected and examined. No whole seeds were 

 found. There were, however, three nearly entire glumes and a 

 pulverized mass of matter which, under the miscroscope, was seen 

 to consist of fragments of broken glumes. Several days later about 

 500 crab-grass seeds were fed to the same sparrows, no gravel 

 being given at the time or during the interval between the two 

 experiments. Twelve droppings were examined and the results 

 were substantially the same as in the first experiment. Three dif- 

 ferent sparrows were then fed with about 1,000 crab-grass seeds 

 and twenty droppings were collected. The result was the same. 

 Not one of the 1,000 seeds was passed in a condition to germinate. 

 Although these experiments are by no means conclusive, yet they 

 strongly indicate that the English sparrow, however harmful it 

 may be in other ways, can not be held responsible for the occur- 

 rence of crab-grass in lawns." 



It seemed desirable, in view of the statement of so careful an 

 observer as Dr. Judd, to institute a series of experiments with the 

 house sparrow and other birds, and the results obtained are set 

 forth below. 



In order to test to what extent, if any, different species of 

 birds were instrumental in disseminating weeds, a quantity of soil 

 was sterilised and then placed in ordinary flower pots, etc. 

 Droppings of the different species were then collected and placed 

 upon the soil and a little fine soil scattered above them. The 

 following tables show the number of plants and species that were 

 thus cultivated, and the number of droppings examined. 



House Sparrow. 



