38 



5TH IOTH I5TH 2OTH 25TH 

 NAME OF SEED YEAR YEAR YEAR YEAR YEAR 



Lepidium virginicum * * * 



Lychnis Githago o o o o o 



Anthemis Cotula * * * o * 



Malva rotundifolia * o o o 



Oenothera biennis * * * 



Plantago major o o o o 



Polygonum Hydropiper o 



Portulaca oleracea o 



Quercus rubra . . . o 



Rumex crispus * 



Setaria glauca 



Stellaria media 



Thuja occidentalis o o o o o 



Trifolium repens o o o o o 



Verbascum Thapsus * ? 



Prof. L. R. Waldron has shown that in the case of 

 some weeds there is delayed germination. He experi- 

 mented with seven different kinds of weed seeds, as fol- 

 lows : Great ragweed or kinghead, wild oats, green fox- 

 tail, shepherd's purse, wild mustard, wild buckwheat and 

 French weed. 



In the fall of 1889 there were planted in a seed bed out 

 of doors at depths of I, 2, 3, 4, 5, 7, and 10 inches the 

 above seeds. During the same fall shepherd's purse pro- 

 duced a few plants at depths of i and 2 inches ; French 

 weed, 25 plants at I inch ; wild mustard, many plants at 

 i, 2, and 3 inches; wild oats, several plants at i, 2, and 3 

 inches. 



During 1900 the seeds continued to germinate, and it 

 was true of them that the small weed seed did not come 

 up through 2 inches of soil; no seeds buried below 3 

 inches germinated except kinghead or great ragweed 

 and wild oats, which came up through 5 inches of soil. 

 The writer, Miss King and Mr. Fawcett have conducted 

 some experiments on delayed germination of weed seeds. 



It was found that the seeds of different species showed 

 great differences in germination ; in general the results 



