310 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



leaves of a much darker green, in all, except the tomatos, a copious 

 branching, and in no case was any delay in flower-production to be 

 seen. It has been stated that the root-system was markedly influenced 

 in the experiments made in some other places, but examination of the 

 roots of several of the plants grown in this series showed nothing more 

 in this direction than was to be expected if the larger foliage was to be 

 sufficiently supplied with water. 



A comparison of the growth of plants in soil and bacterized peat, 

 and that in soil and untreated peat, shows that the water-retaining 

 power of the peat is not sufficient to account for the differences in 

 growth of plants in soil containing bacterized peat and in loam, 

 respectively. 



A somewhat remarkable thing is the comparatively slight difference 

 in growth observed with the varying quantities of peat, for little extra 

 growth and no detrimental effect were to be observed when the amount 

 of bacterized peat reached half the content of the pot. If anything in 

 these experiments lends support to the theory of the presence of 

 " activators " it is this curious result. 



II. Series ib. — Experiments on Plants growing in Sand and 

 watered with Peat extract. 



The plants used in this series of experiments were tomatos. 



Sixty seedling plants of the same size and age were planted in 

 washed silver-sand in 6o-sized pots. These plants were divided into 

 five sets as follows : — 



12 watered with a water extract of bacterized peat. 



12 with a water extract of boiled peat. 



12 with a water extract of untreated peat. 



12 with an ammoniacal-water extract of untreated peat. 



12 with water alone. 



The plants were watered with the extract in question once a 

 week, plain water being used at other times as required. Tap water 

 was used in every case. 



The plants watered with the ammoniacal extract all died within 

 two days. A few of each of the other sets died from time to time, 

 but a sufficient number of each survived to enable us to see the result 

 of the treatment. 



None of the plants grew really well, but those watered with the 

 extract of bacterized peat much out-distanced the others. The 

 leaves in these plants attained a length of three inches, while in none of 

 the others was there any exceeding about one and a half inch after 

 five weeks' growth. There was practically no difference between the 

 plants watered with either of the other peat extracts and those watered 

 with tap water. 



It seems obvious from the results of this series of experiments that 

 the value of the peat lies in the water-soluble contents after treatment, 

 and that mere heating does not bring about the change necessary to 

 give it this value. 



