292 
Kusano, Further Studies on Aeginetia indim. 
highly inconspicuous. The formation of the tuhercle has already 
heen observed in Orohanche, in which however only one fifth of 
the whole length of the seedling is transfered into it. 
The frontal portion of the tubercle penetrates into theyoung 
cortex of the host-root and becomes differentiated into a primary 
haustorium which is completed by the formation of tracheids in 
direct connection with the conducting System of the host-root. 
On the completion of the haustorium the tubercle derives nourish- 
ment from the host, and there ensues a vigorous development. 
The further development of the tubercle — formation of the shoot 
and root-system — is quite the same as in Orohanche (Koch 
1883). 
Germination-Experiments. 
As has been quoted above, there is no doubt that in the 
germination of the Orobanchaceae, as ascertained in Orohanche 
and Lathraea, a Chemical Stimulus comes into play. Still it has 
not been conclusively shown that whether the Stimulus in question 
is due to the character of the roots as such, or is entirely peculiar 
to the root of the proper host. Although Koch has expressed the 
opinion that „die Samen der Orobanchen keimen nur im Anschluß 
an die Wurzel einer geeigneten Nährpflanze“ (Koch, 1883, p. 188), 
it seems to me that a sufficient number of plants has not been 
tested with this point in view. Heinricher (1894) succeeded in 
raising the seedling of Lathraea on the roots of a very few kinds 
of trees. From his experiments we cannot conclude that the roots 
of aU trees can stimulate the seed to germination. A further 
study is also needed to decide whether the seed germinates on the 
roots of herbaceous plants. But when we consider that these 
parasites thrive only on certain plants i) one might consider himself 
justified in assuming that the germination takes place only on 
these plants. Likewise, as only monocotyledonous plants are at 
present known as the hosts of Aeginetia in the field^), one might 
be led to the same assumption. This has, however, been proved 
to be quite incorrect by the germination-experiments now to be 
described. As these experiments were originally planned to veri- 
fy what we had assumed, they were not so extended as were after- 
wards found desirable. 
q Among more than 300 species enumerated by von Beck (1890) as 
the hosts of Orohanche no monocotyledonous plant is mentioned as the proper 
host. 
q So far the following plants have been asceHained to serve as the host: 
Ganna indica L. (Dandoku). Carex lanceolata Boott. (Hikagesuge). C. Mor- 
rowi Boott. (Kansuge). C. transversa Boott. (Ko-onisuge). Imperata anm- 
dinacea Cyr. var. Koenigii (Benth.) Hack. (Chugusa). Miscanthiis sinensis 
(Anders.) (Susuki), M. sacchariflorus Hack (0^). Oryza sativa L. (Upland 
form) (Okabo). Panicum miliaeeum L. (Kibi). P. flumentaceus L. (Hie). 
Saccharum otficinarum L. (Satokibi). Setaria italica Kth. var. germanica Trin. 
(Awa). Zea Mays L. (Tomorokoshi). Zingiher Mioga Rose. (Myoga). 
