298 Kusano, Further Studies on Aeginetia indica. 



In Aeginetia the formation of the hair-tendrils is alone sufficient 

 to avoid such a danger. 



In the second place, Aeginetia shows some transitional states 

 between autophytic and the most advanced parasitic life. In most 

 hemiparasites, or more strictly speaking, green parasites such as 

 Santalaceae (Kusano, 1906, Barber 1906, 1907), ßhinanthaceae 

 (Heinricher, 1901, 1902) and Loranthaceae, the germination is 

 neither associated with the presence of the host, nor have they 

 any marked tendency to select their host. But some holoparasites 

 or at last Orobanchaceae, hitherto studied, have acquired thehabit 

 of not developing and even of not germinating without the presence 

 of the roots of their proper host. While thus the intimate relation 

 of the parasite and host-root is in this case restricted to certain 

 limited species of plants, Aeginetia shows itself to be many-sided 

 in this respect: In Orobanche and Lathraea the selection of the 

 host takes place already at the period of germination, it takes 

 place in Aeginetia at a later period. Thus certain variations ob- 

 served to occur in the Orobanchaceae in their behaviour towards 

 the host-roots a study of other species of the same family is very 

 desirable. 



The chief results of the experiments described in the fore- 

 going pages may be summarised as follows: 



1. The germination of Aeginetia- seed does not take place in 

 water, moist Chamber or soil. It requires always the Stimulus of 

 the root of other plants. 



2. The seed kept dry for two years loses its germinating power. 



3. The plants which stimulate the seed to germination may 

 be Vascular Cryptogams, Gymnospernis, or Angiosperms. 



4. The stimulant is an unknown substance that is perhaps 

 excreted by active roots of all higher plants. 



5. The development of the seedlings takes place only on 

 certain species of Monocotyledons. Its conditions are entirely 

 diiferent from those that are necessary for the germination of the 

 seeds, the former being fulfilled only by certain plants while the 

 latter are found in the roots of all higher plants. 



6. The first change that takes place during the germination 

 is the swelling of the epidermal cells at the radicular end of the 

 embryo and their transformation into the hair-tendrils. 



7. The seedlings are much reduced in form, and before they 

 are connected with the host no multiplication of cells take place. 



8. The seedlings develop, when attached to the host, spherical 

 tubercles. They are formed by the meristematic tissue under the 

 hair-tendrils. 



9. For the multiplication of cells in the seedlings certain 

 Stimulus from the host-roots to which the hair-tendrils are sensitive 

 seems to be required. . 



10. The tubercles become differentiated first into the primary 

 haustorium at the frontal portion, and then into the shoot and 

 root-system at the other portions. 



Botanical Institute, Agricultural College, Tokyo. 



June, 1908. 



