Kusano, Further studies on Aeginetia indica. 287 
proper host-root. In this plant the embryo is so mucb reduced in 
form as to appear like a yonnger stage of a dicotyledonous embryo 
(Koch, 1878, p. 259), being merely an oval cell-mass, and tbe 
cbanges tbat take place during germination sbow certain pecu- 
liarities. At first tbe radicular half of tbe embryo develops into 
a filamentous root (Kocb, 1883, p. 189), wbile tbe plumular half 
remains tbrougbout in tbe endosperm, acting as an absorbing organ. 
Differing from Za?f/^raea-seedling tbe parasitism of tbis seedling is 
effected by tbe root-tip, provided it abuts on a bost-root lying be- 
force its course. In bis culture-experiments Kocb (1883) assumed 
tbat in germination tbe seeds required a cbemical Stimulus from 
tbe bost-root. Such being all tbat we know, at present, about tbe 
early stage of development of tbe Orobanchaceae, it appears to 
me^ to be not tbe less interesting to extend our study on Aeginetia 
wbicb exbibits a dose resemblance to tbe last mentioned species 
of Orobanchaceae, on account of tbe structure of tbe seeds as well 
as tbe vegetative Organs, and to ascertain bow far wbat was found 
on tbe latter plant is applicable to tbe former. 
Wbile tbe present study was carried out witb tbis end in 
View, I bave never undervalued tbe problem about tbe condition 
wbicb tbe seeds of such boloparasite require in germination. Al- 
tbougb it bas been ascertained by tbe above mentioned autbors 
tbat tbe Stimulus of tbe bost-root is invariably neccessary to ger¬ 
mination in plants of tbis family, tbe nature of tbe Stimulus bas 
not yet been studied witb accuracy. Concerning tbis point I can 
not yet express any definite view, but as it seems to me tbat tbe 
results of a few incidental experiments are suggestive for a furtber 
study on tbis subject, I will note tbem briefly in tbe present paper. 
Methods. 
Tbe seed of^ Aeginetia being very fine and pulverous, a special 
treatment is required in observing its germination. In order to 
observe easily tbe successive stages of germination, and of tbe 
development of tbe seedlings, I transplanted, a montb or two pre- 
viously, some vigorous bost-plants in pots of 15—20 cm in diameter. 
Tbese being kept sufficiently moist, tbe plants began to produce 
after a wbile young rootlets mainly traversing between tbe wall 
öf tbe pots and tbe soll inside. Wben a tbick mesb-work was 
tbus formed by tbe rootlets I lifted up carefully tbe plants from 
tbe pots, laid tbe seeds of Aeginetia upon tbe mesbes, and tben 
put tbe plants again in tbe pots as before. By taking tbe plants 
from time to time out of tbe pots witbout disturbing tbe arrange- 
ment of tbeir root-system on wbicb tbe seeds were laid, I was 
able to follow in detail tbe cbanges tbat took place during tbe 
germination and subsequently. 
Tbe seeds used in tbe experiment were collected in tbe pre- 
ceding year and kept dry. Under favourable conditions tbey ger- 
minated witbin two weeks in tbe early summer. However I could 
observe no germination to take place in seeds preserved in a 
