274 Brenchley\—Organic Plant Poisons. II. 
a lower strength of poison the laterals showed an inclination to behave the 
same way at first, but before very long they pushed out well and the plants 
improved very greatly, approaching the controls. The shoot-root ratio 
remained fairly constant allthrough. The same mould as was obtained with 
pyrogallol (Nectria cinnabarina) was observed floating in the solution. 
Orcinol. 
Strong solutions of orcinol, M/ioo, acted unfavourably on the roots of 
peas from the outset; as the tips became flabby within twenty-four hours 
of insertion in the solution, and within three days the whole root was 
involved. Within a week all the roots were flabby and constricted and 
gYe.-ms 
Fig. 17. Average dry weights of ten 
series of pea plants grown in strong nutrient 
solutions in the presence of differing amounts 
of orcinol. Oct. 15, 1914-Jan. 21, 1915. 
N.B. 5 5 Upper curve = mean dry weight 
of plants which made fair recovery. Lower 
curve = plants which made poor recovery. 
moulds had appeared. Curiously, though, the shoots were not checked at 
the beginning and for the first week their growth almost equalled that of the 
controls, but this initial spurt was not maintained, as after a fortnight no 
further progress was made. Nevertheless the shoots did not wilt or die at 
all easily, as nearly a month passed before they began to get flabby. 
Meanwhile the moulds on the roots made rapid progress, and ultimately no 
signs of life remained in the plants. 
With rather lower concentrations, M/ioox^, the roots were injured 
from the first, though they were not killed. They were discoloured and 
made poor laterals, which remained short and stubby for some time. 
Growth was at a standstill for a period, but after the lapse of two months 
new laterals appeared, which remained short in some cases and elongated 
into normal rootlets in others. This continued to the end, and the ultimate 
Fig. 16. Average dry weights of ten 
series of pea plants grown in strong nutrient 
solutions in the presence of differing amounts 
of phloroglucin. Oct. 10, 1914-Jan. 19, 
1915. 
effect on growth is shown by the two parts of the curve in Fig. 17, which 
