Kusaiio, Further Studies on Aegimtia iudica. 
291 
securing’ as many chances to meet with a desked host-root, but 
that as soon as one of tbe tendi^ils comes in contact witb it the 
seedling does not need tbe development of further tendrils. 
Usnally only tbe apex of tbe tendril is responsive to tbe 
Stimulus, but tbat tbe otber portions may also react may be seen 
in Fig. 11, wbere a tendril is sbown twining aronnd a root-bair 
of a proper bost-root {Zingiber). 
Tbe tendril on coming in contact witb tbe bost seems to be 
retarded in growtb as in tbe typical tendril (Fitting, 1903, p. 604), 
and it seems to wither and die away if kept indefinitely away from 
a proper bost. 
In view of all tbese facts tbere can be any donbt tbat tbe 
bair in seedling is quite different botb morpbologically 
and pbysiologically from tbe true root-bair, and that it most closely 
resembles tbe typical tendril in its function. 
Wbile the changes described above are taking place at tbe 
radicular end, we can not find any notable cbange at tbe plumular 
end except for a sligbt increase in size. Tbe general form of tbe 
embryo at tbis stage is tben as reproduced in Fig. 12. It is 
perbaps tbe last stage to wbicb an embryo can develop witbout 
coming in contact witb tbe bost-root. Much starcb-granules still 
remain in tbe embryo and endosperm, and serve as tbe reserve 
material for the further development of tbe seedling. 
Tubercle and Primary Haustorium. 
Wben a seedling as above described comes in contact witb 
a bost-root by means of a bair-tendril further development follows 
immediately. By a rapid multiplication of cells tbe seedling grows 
so as to become visible to tbe naked eye. Tbe newly produced 
tissue gives rise. besides a primary haustorium, to a tubercle from 
wbicb tbe sboot and root-system of tbe plant are afterwards formed. 
Wbat is remarkable is that tbe multiplication of cells does not 
take place unless the seedling becomes attacbed by one of tbe 
tendrils to tbe bost. Since tbe seedling is otherwise entirely in- 
capable of fui'tber development in spite of tbe presence of tbe re¬ 
serve material left in tbe endosperm, it follows tbat tbe further 
development of tbe seedling is associated witb tbe Stimulus of tbe bost. 
The multiplication of cells occurs under the tendril-cells. Tbe 
parencbymatous tissue tbus derived pusbes and finally breaks tbe 
latter, and comes to lie in direct contact witb tbe tissue of tbe 
bost-plant. Until an organic connection becomes establisbed between 
tbe seedling and tbe bost-tissue tbe multipbcation of ceUs must 
be due to tbe reserve material in tbe seed. Tbe maximal size to 
wbicb tbe cell-niass can tbus attain is less tban 1 mm in diameter, 
approximately tbe same as tbat to wbicb tbe seedling of 
can reacb witb tbe belp of its endosperm alone (Koch, 1883, p. 189). 
Tbe cell-mass tbus formed becomes a tubercle generally of 
a spberical or oval form (Figs. 13, 14). It forras a large part of 
tbe seedling, making tbe plumular end, globular cells and tendrils 
19* 
