292 Kusano, Further Studies on Aeginetia, indica. 



highly inconspicuous. The formation of the tubercle lias already 

 been observed in Orobanche, 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 Orobanche (Koch 

 1883). 



Germination-Experiments. 



As has been quoted above, there is no doubt that in the 

 germination of the Orobanchaceae, as ascertained in Orobanche 

 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 all 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 1 ) 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 2 ), 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. , li8( , 



, ( 19ft,Bl 



x ) Among more than 300 species enumerated by von Beckll 

 the hosts of Orobanche no monocotyledonous plant is mentiongd ^(jfche^roip^ 



host ' . ,60'i 9ifo Oi 9nb 9d 



2 ) So far the following plants have been asceH^inedgto ser.ye £ ,ae ; ;the.bjOBt: 

 Canna indica L. (Dandoku). Carex lanceolata Boott. (HiKagesuge?. .UTMor- 

 rowi Boott. (Kansuge). C. transversa Boott. . (Ko-ÖlrJsugW.' ^ifflp&aW^ätyikbß 

 dinacea Cyr. var. Koenigii (Benth.) Hack.^(%i\igtii^^dMi^Mhük>täneifäi$ 

 (Anders.) (Susuki). M. sacchariflorus Haßfe(i(<i)lgi).an0? - ?/Mßfi^lfei'''j I*.Q fr (Up_land 

 form) (Okabo). Panicuni miliaceiim£ % $j. p^fy 

 Saccharum officinarum L. 

 (Awa). Zea Mays L. (Tomorokos 



aecnarijtorus ±iacjc ii!,vJtglp:iJ UXU'-a ■'.-■■ sv*tW\ J^-ü lupiana 

 j. (SatokihtJ. " beiarrti/falica^Kth, v.ar. germanica Irin, 



