71 



RuDGE, Ann. of Bot., X, 1896). As yet nothing is known con- 

 cerning the development of the recently described Archangiop- 

 teris from southern China. All of the genera that have been 

 described agree in the main characters of the prothallinm and 

 reproductive organs, which differ decidedly from those of the 

 leptosporangiate ferns. As Jonkman showed, and as I can 

 confirm from a study of 3/arattia Douylasll, the small colorless 

 spores first develop chlorophyll and enlarge to several times 

 their original size before the first division takes place. The 

 growth of the prothallinm is very slow, and according to Jonk- 

 man the reproductive organs appear only after a long period. 

 This slow growth and the difficulty of keeping them in culti- 

 vation free from algae and fungal parasites accounts for the 

 failure of most attempts to grow them. 



Where the plants are found growing in their native habitat 

 careful search will usually reveal more or less numerous pro- 

 thallia; but as most of the species are not very common it 

 requires a good deal of searching to obtain these. 



The gamethophyte of the Marattiaceae is easily distinguished 

 from that of most ferns l)y its dark green color and fleshy 

 consistence. Except at the extreme margin it is more than one 

 cell in thickness, and the deep green color and texture both 

 are suggestive of AntJtoceros. 



The prothallia of Kaulfassia are much larger than those of 

 any other Marattiaceae that have yet been described and, 

 except for the large branching prothallinm of certain species 

 of Hi/inenophi/IIum and ViUarla, are the largest that are known. 

 Unlike Hymenophijllam and Vittarla, where the filmy prothal- 

 linm is but one cell thick, the large prothallia of Kaulfussia 

 are very massive and strongly resemble such a liverwort as 

 Pellia or Aneura. 



The youngest prothallia that I secured were about 5 mm. 

 in length and like the older ones were decidedly elongated, with 

 a deep sinus in front (PI. VII, Figs. 1 and 2). Antheridia were pre- 

 sent in small numbers, occupying the forward part of the thick 

 midrib, which is strongly developed in Kaulfussia as it is in 



