Kusano, Further Studies on Aeginetia indica. 295 



shown in Fig. 4, they ultimately came to death, mainly owing to 

 mould fungi or other microorganisms. 



The foregoing experiments show, contrary to our natural ex- 

 pectation, that the Stimulus necessary for the germination of 

 Aeginetia-seeä is not peculiar to particular species of plants, but 

 is given by all vigorously developing roots, whether of Phanero- 

 gams or Yascular Cryptogams. If it be admitted that a chemical 

 Stimulus is concerned here, it is most probable that the stimulant 

 is an excretion of the roots. The foüowing experiments afford 

 some evidence for this view. 



2. Germination of Seeds wrapped in Paper on Pot-Plants. 



This experiment was undertaken to ascertain whether the 

 direct contact of the seed with the host-root is neccessary for ger- 

 mination or not. The seeds were wrapped in one or several sheets 

 of well washed filter-paper and laid among the root meshes of the 

 pot-plants. For control seeds prepared in the same manner were kept 

 at the same time in a moist Chamber, and again unwrapped seeds were 

 laid directly on the roots of the same pot-s. The seeds wrapped in 3 — 5 

 sheet sof paper did not germinate about the time that the unwrapped 

 seeds germinated vigorously. However those wrapped in one sheet 

 and laid on Zingiber and Pollia germinated partly. In the mean 

 time the control seeds in the moist Chamber remained entirely 

 unchanged. 



From this experiment we see that direct contact of the seeds 

 with the host root is by no means an indispensable condition in 

 bringing them to germination, and that the germination is associated 

 with a certain substance or substances excreted by the host-root 

 and diffused into the surrounding medium. That the percentage 

 of germination is smaller in the case of the wrapped seeds than 

 in those laid directly on the root, and that it becomes less with 

 the increase of the sheets of paper are strong evidences that the 

 amount of the diffusible substance depends upon the nature of 

 medium through which it must pass to reach the seeds. 



3. Germination of Seeds without Host-Root. 



The seeds were kept in water (tap-water or destilled water) 

 or in a moist Chamber. They were also sown in soil without any 

 visible plant. In either case I was not able to observe any sign 

 of germination. If such seeds were afterwards brought on the 

 root of any plant, the germination took place easily. Hence it 

 follows that the seed of Aeginetia always requires a Stimulus from 

 the roots for germination. 



4. Germination of Seeds in Chemicals. 



This is only a preliminary experiment to find out a stiniu- 

 lating substance among chemicals, and only a few substances were 



