10 THE OPHIOGLOSSALES 



early divisions. In these larger prothallia there is already the beginning of an axial 

 tissue. Whether the cell x (plate i, fig 9) is to be regarded as an apical cell, it would 

 be hard to say. 



Owing to my departure from Java about three months after the first observa- 

 tions were made, it was impossible to trace the development of the prothallia further, 

 but this much is certain — without the infection of the fungus, growth will not pro- 

 ceed beyond the three-celled stage, and apparently in 0. pendulum no chlorophyll 

 will develop under any conditions, and the prothallium from its earliest stages must 

 be considered saprophytic in its nutrition. Whether the oval body described as the 

 product of germination is to be considered as a sort of tubercle, such as is found in 

 Lycopodium cernuum, must be decided by further investigations. Lang's descrip- 

 tions and figures of the smallest specimens which he discovered would indicate 

 that this is not the case in O. pendulum; but the tuberous body usually found at the 

 base of the older prothallia in 0. moluccanum (and this is true also in O. vulgatum) 

 would indicate that in these species it is not impossible that a primary tubercle 

 is first formed and subsequently the fertile branch. 



THE ADULT GAMETOPHYTE OF OPHIOGLOSSUM. 



In 1856 Mettenius (Mettenius 1) found the gametophyte of O. pedunculosum 

 Desv., a tropical species, growing spontaneously in the pots where the plants had 

 been cultivated in the botanical garden at Leipzig. He did not succeed, however, 

 in making the spores germinate. These prothallia were slender, subterranean 

 bodies, sometimes branched, sometimes without branches. They ranged in length 

 from 1.5 lines to 2 inches (fig. 3, A, B). There was usually present a basal enlarge- 

 ment or tuber, from which the fertile part of the prothallium extended. The older 

 portions were brov?nish in color; the growing tips of the branch white. From the 

 surface there grew numerous short brown rhizoids. Archegonia and antheridia 

 grew more or less intermingled and were formed in large numbers. Except for the 

 greater size, these prothallia closely resemble those of O. moluccanum collected by 

 me in Buitenzorg; and as 0. pedunculosum Desv. has been held to be a synonym 

 of O. moluccanum Schlecht, it is possible that Mettenius's plants were the same as 

 those found by me growing in Buitenzorg in Java.* 



The next account of the prothallium of Ophioglossum is that of Lang (Lang 1). 

 He collected in Ceylon specimens of the prothallia of Ophioglossum pendulum. 

 These were found in the Barrawa Reserve Forest, not far from Colombo, and were 

 buried in the humus accumulated between the leaf bases oi Poly podium quercifolium, 

 an epiphytic fern to which 0. pendulum is often attached. I visited this same locality 

 in February, 1906, but was unsuccessful in collecting the prothallia, although I 

 obtained numbers of the sporophytes. Some time after, however, when in Java, I 

 found a very large number of prothallia which were growing in much the same way 

 as those collected by Lang, except that in this case the fern to which the Ophio- 

 glossum was attached was the widespread bird's-nest fern, Asplenium nidus. 



Bruchmann has given a detailed account of the prothallium of the widespread 

 0. vulgatum, which agrees closely in its essential details with O. pedunculosum and 

 0. moluccanum. Bruchmann's specimens were collected in the Thuringian Forest, 

 in a depression that was subjected at times to overflow, a condition paralleled by the 

 locations where the prothallia of Helminthostachys were collected by Lang and 



* Cristensen in his recent Index Filicum (1906) regards 0. moluccanum as a synonym of 0. pedunculosum. Through the kind- 

 ness of Professor K. Goebel, I recently had an opportunity of examining some specimens of 0. pedunculosum growing in the 

 botanical garden in Munich. These plants were the descendants of the specimens in Leipzig described by Mettenius and certainly 

 very closely resembled the typical 0. moluccanum from Buitenzorg. 



