155 



looked for small sporophytes which might be attached to the 

 buried gametophyte, but the smallest leaves seen reached a 

 leugth of 10 centimeters or more, and had not at all the aspect 

 of belonging to germ plants. These in all cases were found 

 to grow from a tuberous body attached to the buried roots. 

 However, when the humus in which these were growing — 

 which was packed tightly between the broad persistent leaf 

 bases of the fern — was examined, in a number of cases 

 the prothallia were found. In one instance several hundred 

 were collected from one large plant of As])lenium Nidus. In 

 no cases, however, was the leafy bud growing directly from 

 the gametophyte. The prothallia closely resemble Lang's figures 

 and descriptions, but are in many cases very much larger and 

 more extensively branched than any of the specimens collected 

 by him in Ceylon. In strong contrast to the prothallium ot 

 0. moluccanum, the gametophyte of 0. pendulum is extensively 

 branched. It often forms a somewhat stellate mass, but is 

 usually very irregular in form (Figs. 34 — 42). The branches 

 penetrate in all directions between the dense tangle of roots 

 which the Asplenium sends into the humus between the per- 

 sistent leaf bases, and on pulling back these leaf bases a mass 

 of fine humus is held together by the mat of roots and can 

 be removed intact. The prothallia are excessively brittle, and 

 it is practically impossible to remove the large ones without 

 a loss of some of the numerous branches. These break oif and 

 no doubt naturally serve to propagate the gametophyte, which 

 apparently is capable of unlimited growth in this way. It is 

 often impossible to say whether the smaller ones that are 

 found loose in the humus are anything more than branches 

 which have become spontaneously sepai-ated from the larger 

 ones. A small number of living s])ecimens were brought back 

 to America in masses of the humus, kept moist in stoppered 

 bottles, and these have grown and are in a perfectly normal 

 and healthy condition at the present time. 



The older parts of the gametophyte are dark brown in color, 

 but the tips of the branches are white, as in O. moluccanum. 



