■S A TIT. 10. — S. KUSANO : STUDIES OX TTTE PARASITISM 



spitze sich nie zum Haustorinm umbildet, sicher alter geschieht 



das nur selten." 13 



The terminal position of the haustoria of Buchleya may be 

 asci'ibed to the same cause, and this may be most clearly proved 

 by a comparison of the various stages of their development, which 

 display an apparent transition from the lateral to the terminal 

 position. Considering at first a young haustorinm, which lies 

 laterally to the mother-root, we frequently find that the part of 

 the mother-root beyond the point where the haustorinm is emitted 

 is retarded in growth (Fig. 5. a, pr), and this difference of develop- 

 ment beyond and behind that point becomes more obvious as the 

 root advances in age. That portion of the mother-root which lies 

 beyond the haustorinm and is retarded in growth, comes to ob- 

 literate gradually until ;it last it is cast away, leaving behind merely 

 a small process or a sear at a certain point of the haustorinm 

 (Fig. 5. b, c). But in an old, vigorously grown haustorinm, even 

 such a scar becomes indistinguishable and thus the haustorinm 

 becomes apparently terminal (Figs. 2 b, c ; 3t; 4). The above 

 stated facts regarding the position of the haustorinm are not dif- 

 ficult to understand, if we examine its anatomical construction. 

 The fact of the modification of the root-tip to the haustorinm 

 seems questionable to me, though Heinriciter, as above cited, 

 stated that this takes place in some rare cases, because the young 

 root of Bucldeya is provided, as usual, with a root-cap as well 

 as with root-hairs. 



Sometimes it is not easy to mark off exactly the connecting 

 part of the haustorinm from the mother-root, in the case of the 



1). IIeinrichkt;. Biologische Studien an dir Gettung Lathrrea. Ber. d. deutsch. 1ml. 

 Gesellsch. Bd. XI, is*). - '., p. 9. ■ -, Ueber Lathrtea Squamaria. Sep.-A.bdrk. ans d. Ber. d- 



natunviss. -medic. Vereins in Innsbruck, XXI LS92/93. 



