21 



that no sélection from the germplants should be made. 

 At the middle of July the young plants were placed in 

 the beds at such distances from each other that each could 

 freely develop. 



Already at the beginning a considérable différence between 

 the two cultures could be observed in ail three species 

 sown in the garden. The seed in the bed that had been 

 manured with hornmeiil came up sooner and the plantlets 

 developed much more vigorously. With Maloa vulgaris the 

 différence between the plants of the two beds was at 

 first very great. Those on the fertile soil showed already 

 abundant leaves and flowers when the plants on the sandy 

 soil had only formed few and small leaves. This différence 

 remained till the beginning of July, when suddenly also 

 the plants on the meagre soi! began to develop vigorously, 

 so that in the autumn scarcely any différence could be 

 observed. The reason of this late, very rapid development 

 appeared when the plants were dug out. It turned out, 

 namely, that some of the strongest roots had reached the 

 underlying earth through the layer of sand. As long as the 

 plants only obtained their food from the sand, they remained 

 tiny and backward, but when the roots had penetrated 

 into the fertile earth they still developed vigorously and 

 with great rapidity. Also with Iberis amara the roots 

 appeared to hâve reached the earth underneath, but in a 

 much less degree. It was difficult hère to trace the fine 

 terminais of the principal roots as far as the underlying 

 earth, whereas the roots of Maloa vulgaris, wiiere they 

 passed from the sand into the earth below, were strong 

 and penetrated at least a few décimètres. Of Ranunculus 

 arvensis only few roots had reached the underground with 

 their tips, the same being the case with Scandix Pedtn- 

 Veneris and Anethum graveoletis ; the roots of Cardamine 

 hirsuta were restricted to the sand, as far as I could see. 



Although with most of the species studied the nutrient 



