12 ART. 10. — S. KUSANO : STUDIES OX THE PARASITISM 



root and so am unable here to compare the formation of the fold 

 in the two kinds of roots. I can state only that in Buchleya, 

 though numerous folds develope even on dicotyledonous and co- 

 niferous roots, they differ in certain respects from those of Tkesium 

 formed on monocotylcdonous roots, for we find in the former that 

 the outermost fold is always the thickest and the largest, adheres 

 to the host-root even after the younger one is formed within, 

 while on the other hand, in the case of Thesium it is generally 

 the youngest fold which is the thickest and the largest, the older 

 folds being lifted away from the host-root. n The cells constituting 

 the folds differ a little from those which are found in the re- 

 maining part of the cortex. Here the outermost cells are arranged 

 compactly and at right angles to the surface and are somewhat 

 elongated in this direction, while the remaining cells do not keep 

 up any definite form or size, being mostly round with wide in- 

 tercellular spaces between them. Along the median region of 

 all folds the cells seem to go into the formation of the striated 

 bands which unite directly with the similar bands in the cortex 

 (Fig. 7). 



The surface of the cortical part, as has been stated above, 

 is covered with corky layers (Fig. 8 ck). The thin and thick 

 walled layers are formed alternately and the older part can be 

 easily stripped oft" layer by layer. The layer extends not only to 

 the exposed surface of the cortical part but also even further to 

 that of the innermost folds, which adhere to the still active 

 cortical tissue of the host, thus leaving only a small portion of 

 the surface in contact with the host uncovered (Fig. 7). By this 

 development of the cork on the contact surface, the passage of 



1). I'lTKA, Inc. eil. Fig. 12 and SoiiMS-LAUBACH, loc. cil. Taf. XXXII, Fig. 1 and 

 XXXIII, Fig. 3. 



