CONTRIBUTIONS FROM THE WISLEY LABORATORY. 309 



was much difference in their height. The results are given below. 

 Only the four pairs of leaves which had been last produced since their 

 repotting were measured and their areas calculated. 



Compost. 



! Plant. 



Area of last 

 eight leaves. 



Total of four 

 plants. 



Loam, 7/8 | 

 Bacterized peat, 1/8) 



I 



2 



3 

 4 



Sq. cm. 

 314*3 

 228-3 



317-8 

 302-8 



Sq. cm. 

 1163-2 



Loam, 3/4 } 

 Bacterized peat, 1/4 ) 



1 



2 

 3 

 4 



258-7 

 256-9 

 4 II 

 206-3 



1132*9 



Loam, 1/2 ! 

 Bacterized peat, 1/2 



1 



2 

 3 

 4 



334'9 

 302-3 



2583 

 286-1 



ii8i-6 



Loam only .... 



1 

 2 

 3 

 4 



2427 

 146-9 



175-9 

 135-6 



701-1 



Loam, 3/4 j 

 Raw peat, 1/4 J 



1 



2 

 3 

 4 



127-1 

 2338 

 231-8 

 144-8 



737*5 



Tomato. — Twenty seedling tomatos were potted up into large 

 6o's in ordinary potting soil, twenty of the same size and age in soil 

 to which one part in eight of ordinary peat had been added, and the 

 same number in soil to .which one part of bacterized peat in eight had 

 been added. These were grown on for some weeks and their behaviour 

 watched. The plants in the soil to which the bacterized peat had 

 been added grew much more quickly than did those in the ordinary 

 soil, or those in the soil to which untreated peat had been added ; their 

 leaves were much darker and much larger. There was little difference 

 between those in the soil containing untreated peat and those in 

 ordinary soil. 



It might have been expected that the luxuriant growth would 

 have caused considerable delay in flower-production, but this was 

 not so. In fact the first flowers were produced by the plants in the 

 mixture of soil and treated peat, and they were borne but little higher 

 up the stem than were those on the plants in ordinary soil. 



No attempt was made to estimate the cropping capacities of the 

 respective sets, as the accommodation available was insufficient to 

 permit of a sufficiently large number being grown on to get an 

 accurate estimate of the fruiting power of the plants. 



General Remarks. — In all these experiments the use of bacterized 

 peat resulted in greatly increased growth, in the production of larger 



