10 AKT. 10. — S. KUSANO : STUDIES ON THE PARASITISM 



A haustorium is made up 'of the outer cortical and the inner 

 axial parts. The cortical part, or briefly the cortex, is composed 

 throughout of parenchymatous cells : those lying at the periphery 

 are larger than the inner (tues, roundish or tangentially stretched 

 and loosely connected together, leaving numerous intercellular 

 spaces between them, while those lying in the inner part arrange 

 themselves regularly, are rich in plasm and are elongated in the 

 longitudinal direction 1 ' (Fig. <S co.). In the median region of the 

 cortical parenchyma along the lateral sides of the haustorium,"' 

 some layers of cells, extending from the apex to the base, 3 ' col- 

 lapse, lose their contents, and their wall becomes pressed together 

 into a striated band , one ou each side 4) (Figs. 7, 8, st). The band 

 and those cells, which surround it and are soon to undergo the 

 same fate, are clearly distinguishable by the absence of any trace 

 of reserve starch-material, from the surrounding parenchyma, which 

 are gorged with it at this period. 



On the apex of the haustorium the cortical part goes into 

 the formation of the attach! ».[/-folds, which overlap the host-root 

 and lie in pairs on both sides of the haustorium itself, the younger 

 folds being formed successively one after another inside the older 

 (Fig. 7 at, at'). The development of these folds seems to depend 

 upon the size of the host : for instance, when the latter is com- 

 paratively young and slender, generally a large thick fold is de- 



1). i. <•., in the direction of the axis of the haustorium. 



2). As the lateral side we designate each half of the haustorium divided by the plane 

 which passes through the axis both of the haustorium and the host-mot. 



3). The end dl' the hanstorinm which adheres to the mother-root is called the base and 

 the other end which terminates in the host the apex or the front of the hanstorinm. 



•l). CHATIN (loa tit.) and I'itka (loc. cit. p. 15) incorrectly regarded such striation in 

 Thesium as being composed of the prosenchymatous cells, but that the striation is really 

 presented by the stretched cell-walls of parenchyma was afterwards shown by Sor.MS (loc. 

 cit. p. 15$). In Burkleya it is composed of a very thin and delicate cell-wall presenting a 

 fine cellulose reaction with chloroiodide of zinc 



