Holloway. — Prothallus, dr., of Tmesipteris. 



407 



starch in and around them, it early forms rhizoids and shows the presence 

 of the fungal coils in its cells. The largest of the embryos borne on the 

 prothallus shown in Plate LXIII, fig. 1, may be compared with that in 

 figs. 58a and 58b. 



Young plants up to 4 mm. in length may frequently be found in which 

 growth is taking place from only one apex. The base of the young stem 

 is smooth and round, and in longitudinal section is seen to consist of 



Figs. 58a, 58b.- — -A protruding embryo in longitudinal section, showing the beak-like 



apex, and also the presence of the endophytic fungus. The sections A 



and B are not consecutive. X 75. 

 Figs. 59a, 59b. — A very young detached prothallial plantlet in longitudinal section, 



showing two apices, each with its conducting-strand. The sections A and B- 



are not consecutive. X 75. 



a uniform tissue. There is no undeveloped apex present at this point. 

 Two such plantlets are figured in my earlier paper (7, figs. 60, 67), and 

 those shown at figs. 74 and 77 in the present paper will serve to illustrate 

 the same point. In the majority of cases when the second apex of growth 

 is formed in such plantlets it arises at the base of the first in just the 

 position it would occupy if it had been initiated in the second epibasal 

 quadrant of the young embryo. This second apex is inclined at a varying 



