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violet. The tracheary tissue is also beautifully differentiated by 

 this stain. The bundle is slightly elliptical in form, and the pro- 

 toxylen] elements appear at the foci of the elliptical section. The 

 first appearance of the tracheary tissue is at some distance back 

 of the apex, and the development appeare to go on rather 

 slowly. In the oldest part of the roots examined, the two 

 xylem masses were unequal in size, the largest showing about 

 half a dozen tracheids in cross section, the other, two or three. 

 Whether the two protoxylems are ultimately joined by inter- 

 mediate tracheal tissue so as to form a continuous plate, as 

 in the roots of the adult plant, cannot now be stated, but in 

 no cases examined was this the case, and it is probable that 

 in the primary root the two xylem masses remain permanently 

 separated. The cells of the foot, as usual, are more or less 

 papillate where they are in contact with the tissue of the 

 gametophyte. They early become infected with the endophyte, 

 which probably makes its entrance from the prothallial tissue, 

 and not from the outside. This point, however, is not perfectly 

 clear. The infected area follows the growth of the young root, 

 but leaves the apical tissues free. 



In 0. moluccaimm. the leaf is the first part of the young 

 sporophyte to develop. In the one large embryo obtained the 

 leaf formed a conical body, merging into a nearly globular 

 basal portion, partly foot, partly the beginning of the root, 

 whose apical cell was already manifest. The leaf shows a 

 definite apical cell , triangular in section, and exhibiting 

 regular segmentation. The inner cells of the segments form 

 the axial strand of tissue which is continued through the 

 embryo into the root. The limits of the two primary organs 

 are quite indistinguishable. The central region which remains 

 surrounded l)y the prothallial tissue is somewhat larger in 

 diameter and the whole of this functions as a foot, al- 

 though it is composed in part of tissue belonging to the 

 root and leaf. The conical young leaf elongates rapidly after 

 it has ruptured the calyptra, and its apex begins to widen 

 out, but still shows a single apical cell (Fig. 13 i). In 



