296 
Kiisano, Further Studies oii Aeginetia indica. 
tested. Uuder a bell jar oue end of a piece of filter-paper moisteiied 
previously witb destiUed water, on wbicb tbe seeds were placed. 
was immersed in a siveii solntion of tbe substance to be tested in 
a small vessel. Bj capillary action tbe given solntion diffuses up 
tbe paper so tbat tbe seeds are acted on by tbe substance in varions 
degTees of concentration at different parts of tbe paper. For 
control tap-water and destiUed water were tested in tbe sanie 
manner. Tbe resiilts were entirely negative, and no germinating 
seeds were observed after two weeks or more. Tbe seeds were 
attacked by motüd fungi and destroyed. Tbe cbeinicals tested and 
tbeb’ concentration in tbe vessels were tbe foUowing: 
Hydrocbloric acid.1/100 and 1/500 mol. 
Pbospboric acid.1/100 and 1/500 mol. 
Tartaric acid.1/100 and 1/500 mol. 
Citric acid .1/100 mol. 
Formic acid.1/100 and 1/500 mol. 
Malic acid .1/10 and 1/500 mol. 
Monopotassinm pbospbate . . 1/100 mol. 
Sodium bj'droxide.1/100 and 1/1000 mol. 
It wonld be of great interest and importance to extend tbe 
above experiments and to determine, if possible, a cbemical or 
cbemicals tbat wonld stimnlate tbe Äeginefia-^QQ^ to germination. 
If sncb a substance be fonnd out, it is bigbly probable tbat it is 
one of tbe excretions of tbe roots. Mncb difficnlty must certainly 
lie in tbe way of such a study. It is generally known tbat roots 
excrete acidic substances (Czapek, 1905, p. 873), and recently 
Schreiner and Eeed (1907) bare fonnd out tbat a very sligbt 
amount of substances is excreted by roots, wbicb act deleterious 
to tbeir growtb 0. Tbe amount is so exceedingl}" small tbat 
it can not be detected by cbemical analysis, but its presence 
is revealed by tbe cbemotropism of roots. Tbe metbod pro- 
posed by tbe last named autbors is very ingenious, and it leads 
US to tbink tbat our germination-experiments, if extended furtber, 
migbt perbaps be appUcable to tbe investigation of root-excretions. 
Development of Tubercle and Selection of Host. 
Altbougb it is clear fi’om tbe foregoing accoimts tbat all 
roots can stimnlate Aeginetia-^QQ^ to germination, stUl tbe facts 
obtained botb from field-observations and ciüture-experiments clearly 
sbow tbat Aeginetia cannot grow on all plants. Tbis is proved 
by my experiments. By careful examination at intervals of tbe 
pot-plants on wbicb tbe seeds were laid, we could ascertain tbat 
tbe germinating seeds did not develop equaUy well on Cryptogams, 
Gymnospernis and Dicotyledons. Again. among l^Ionocotyledons 
different plants acted very dilferently. Tbe plants of tbis group 
tbat induced tbe seedlings to form tubercles were Lujiida, botb 
species of Carex, Calamagrostis, AEscanthus, Setaria, Orgxa, Panicum, 
b Forthe literature on root-excretions see Schreiner and Reed’s paper. 
