38 ART. 10. — S. KUSANO : STUDIES ON THE PARASITISM 



similarity of the structure of the four species till now studied 

 strengthens, in every respect, our view that the haustorium of the 

 above two plants will follow the same fate as that of Buckleya, 

 for instance, as to the mode of the secondary growth as well as 

 to the modification of the structure then occuring, provided they 

 will sustain their activity during many years. 



Lastly I may here say something about the attaching-folds. 

 Their number as well as form are dilferent in different species of 

 hosts ; thus the haustorium of Thesium has numerous attaching- 

 folds on Monocotyledons, but only a pair on Dicotyledons, while 

 in Osyris and Santahaii a single pair is always developed. 11 In 

 Buckleya I found that numerous folds are developed on various 

 dicotyledonous and coniferous roots. But the haustorium of 

 Buckleya on monocotyledonous roots has not yet been found, nor 

 has the number of the folds yet been decided. That the develop- 

 ment of the folds differs with different kinds of hosts — that they 

 are not formed during the secondary growth of the haustorium 

 — that they disappear in old specimens — all these facts lead us 

 to regard them as organs subordinate in their functions and to 

 consider their function of attachment to be but of minor im- 

 portance. 21 



The results of the studies on the structure of the haustorium 

 of Buckleya are briefly as follows : — 



1. The haustorium is provided with a cambium ring be- 

 tween its cortical and axial parts, whereby a continued growth 



] ). Whether the dovelopment of the single pair of the folds in Osyris and Santalum is 

 found on monocotyledonous or dicotyledonous mot is unknown to us. 



2). IIeinkiciieii (loe. cit. p. 328) has already published the same view on the haustorium 

 of Lathrsea: "Wir haben also vor allem gezeigt, dass die „replis préhenseurs," die Zangen- 

 jortsätze, eine yanz nebensächliche Erscheinung an den Ihiustorien sind." 



