THE GAMETOPHYTE 



13 



Fig. 3. 



A, B. Gametophytes of Ophtoglossum pedunculosum (after Mettenius). 



C, D. Gametophytes of . vulgatum (after Bruchmann). 



E-G. Gametophytes of 0. /Je«^u/«m. jp, young sporophyte; f, secondary root. 



(fig 3> C). There is a more or less conspicuous basal tuber, like that found in 

 0. moluccanum, and from this extends a branch bearing the reproductive organs; 

 but, unlike the prothal- 

 lium of O. moluccanum, 

 there seems to be a 

 complete absence of 

 rhizoids. In general, 

 the form is more irreg- 

 ular than that of 0. 

 moluccanum and more- 

 over it is very long- 

 lived. The branches 

 may become detached 

 and thus form new in- 

 dividuals. From the 

 rate of growth in speci- 

 mens kept under ob- 

 servation for several 

 months, Bruchmann 

 concluded that they 

 might live for twenty years or more. Where the apical growth of a branch is 

 interfered with, there may be a formation of adventitious buds, a phenomenon 

 which is also common in O. pendulum. 



Ophioglossum (Ophioderma) pendulum, a remarkable epiphytic species wide- 

 spread through the tropics of the Old World and reaching to Hawaii, is the giant 

 of the order, the pendent ribbon-shaped leaves sometimes attaining a length of 

 1.5 meters. The sporophyte grows rooted in masses of humus, either upon the 

 rough trunk of a tree fern or palm, or hanging from the mass of humus accumu- 

 lated about the base of certain epiphytic ferns. The bird's-nest fern, yf j/)/e«/wm 

 nidus, furnishes the favorite substratum for this species in the forest of Tjibodas in 

 Java, where my material was collected. 



The young prothallium in O. pendulum is an ovoid body, the somewhat smaller 

 forward portion corresponding to the fertile branch in O. moluccanum (see Lang 1, 

 page 25). The older ones become very much larger than in any other species that 

 has been described, and they branch freely in all directions, except as their growth 

 is controlled by their position. They are always found buried in a mass of humus 

 between the imbricated leaf bases of the fern, and are often much flattened by the 

 pressure of the leaves between which they are confined. Branches extend in all 

 directions, but their growth is to some extent controlled by the inclosing leaf bases 

 and also by the tangled mass of roots of the fern, which growin all directions through 

 the mass of humus and among which the branches of the prothallium of the Ophio- 

 glossum extend. In one instance several hundred were collected from one large 

 plant of Asplenium nidus. The prothallia closely resemble Lang's figures and 

 descriptions, but in many cases are very much larger and more extensively branched 

 than any of the specimens collected by him in Ceylon (plate i, figs. 11-14). The 

 larger prothallia may be stellate in form, but they are usually very irregular. The 

 branches penetrate in all directions between the dense tangle of roots which the 

 Asplenium sends into the humus between its persistent leaf bases, and on pulling 

 these back a mass of fine humus is found, held together by the mat of roots so that 

 it can be removed intact. The prothallia are excessively brittle, and it is practically 

 impossible to remove the larger ones without a loss of some of the numerous branches. 



