Dec. 1891.] THE BOTANICAL SOCIETY OF EDINBURGH. 221 



is not unusual to find land lying in grass where only the 

 upper layer of the soil is charged with roots to any notable 

 extent, while the lower layers are lying idle for want of the 

 presence of those grasses which send their roots down into 

 the lower soil and subsoil. The farmer will probably be 

 heard complaining that his land is too dear, and yet he may 

 be found utilising only the upper half of it. By the selec- 

 tion in due proportion of grass seeds of different rooting 

 tendencies, it is natural to suppose that the capabilities of 

 grass land might be greatly increased. It was such considera- 

 tions that led me to make the experiment I have to bring 

 before your notice. 



There are some difficulties in the way of making such an 

 experiment, but the chief one is that of collecting the grass 

 roots in such a way as to lose nothing — not even the 

 smallest hairs. To get over that difficulty, I had a number 

 of pots made of zinc, like the one I now exhibit. It is 2 

 feet deep, with a superficial soil area of 6 inches square. 

 One side of the box is made movable, so that it can be 

 taken off and put on at pleasure. The pots or rather boxes 

 were filled almost to the top with good farm soil made 

 thoroughly homogeneous and well shaken down, and between 

 the movable side and the soil there was placed a sheet of 

 glass to enable me to take off the side without disturbing 

 the soil, aud this I did in the hope that I might be able to 

 see the roots and watch their progress. The mass of roots 

 which one sees sometimes when repotting plants led me to 

 expect that the grass roots might be in part visible, but in 

 this I was entirely disappointed — there was scarcely a trace 

 of a root to be seen at any time during the period of growth. 

 The zinc boxes were all sunk in sawdust in a large square 

 wooden box which was turned every morning one quarter 

 round, so as to expose all the pots equally to the light, &c., 

 and give them all an equal chance. 



The seeds were sown in June 1889, and the crop was cut 

 and the roots were taken out in end of June 1890, so that the 

 quantities of vegetable matter produced represent only the 

 first year's growth. 



In taking the plants out of the earth each box w^as laid 

 on its back, the movable side and the glass below it taken 

 away, and tlie whole was immersed in water in a large sink 



