122 THE MARAITIALES 



prothallia, which may be detached and become independent plants; or reproduc- 

 tive organs may be developed upon them, usually only antheridia, while they are 

 still connected with the mother plant. The prothallia are very long-lived and 

 apparently may grow indefinitely so long as the archegonia are not fecundated. I 

 kept prothallia of Marattia douglasii for nearly two years, during which time they 

 grew vigorously and finally reached a length of over 2 centimeters. At the end of 

 two years there was no indication of the slightest decrease in their vigor. 



The prothallia are monoecious, although it is not uncommon to find small 

 prothallia which bear only antheridia. They are very deep green in color, which 

 together with their more massive texture makes them easily distinguishable from the 

 prothallia of the ordinary ferns, and they very often look more like such a liverwort 

 as Pellia or Anthoceros. The prothallium oi Angtopteris very closely resembles that 

 oi Marattia, but is often somewhat shorter. The difference in shape in the prothallia 



of the form studied by Jonkmann {A. 



priiinosa var. hypoleuca) and the Cey- 



lonese form studied by Farmer and my- 

 ew?-/-^ ^^ \ I '1^^ '^^ self may be taken as an argument in favor 



of recognizing a specific difference between 



these two forms. 



The archegonia in both Marattia and 



Angiopteris, so far as my own observations 

 Fig. 89. extend, are confined to the lower surface 



Two gametophytes of Angiopterh with young sporophyte of the midrib. TonkmanU, hoWCVCr, StatCS 

 attached, em, embryo; co/, cotyledon. X3. . • 11 1 1 i 1 



that occasionally he observed archegonia 

 developed upon the upper surface as well. The antheridia, while more abundant 

 upon the lower surface of the prothallium, are quite commonly met with also upon 

 the upper surface and are not restricted to the midrib, but may be found quite near 

 to the margin. The rhizoids in both Angiopteris and Marattia are probably always 

 unicellular, and their walls, which are quite strongly cutinized, are dark brown in 

 color. 



THE PROTHALLIUM OF KAULFUSSIA.* 



The prothallia of Kaulfussia are usually much larger than those of either 

 Marattia or Angiopteris. They are very massive, strongly resembling a Pellia or 

 Aneura. The specimens described here were collected in Java in a small ravine 

 near the foot of the volcanic mountain Salak. The youngest prothallia found 

 were about 5 millimeters in length and, like the older ones, were decidedly elon- 

 gated, with a deep sinus in front (fig. 90, A, B). There were a few antheridia 

 occupying the forward part of the thick midrib, which is very largely developed 

 in Kaulfussia, as it is in the other Marattiaceae. The older prothallia are relatively 

 somewhat broader and these larger ones usually bear archegonia. Only in a 

 few cases were young antheridia found upon the prothallia with the archegonia. 

 Whether this is always true could not be decided from the small number of prothallia 

 found. The antheridia in Kaulfussia seem to be strictly confined to the lower sur- 

 face of the midrib and occupy much the same position that the archegonia do. 

 After the antheridia have matured and discharged the speimatozoids, archegonia 

 arise in the same position in regard to the apex. Unlike most ferns, the walls of the 

 empty antheridium do not become discolored, so that they are easily overlooked. 

 Careful examination of the sections of the older prothallia, however, will almost 

 always show the empty antheridia and it is probable that the prothallia are usually 



* Kaulfussia Blume = Christensenia Maion. 



