ReEcENT Fern LITERATURE 59 
the walking fern grown on a nutrient solution which was 
purposely not renewed for long periods, so that the pro- 
thallia were partially starved. Other investigators 
have concluded that, in cases observed by them, apog- 
amy was induced by too much light and too little mois- 
ture for fertilization. Mrs. Brown, however, considers 
that in this instance it was due rather to insufficient 
nourishment. - From the fact that only one case of apo- 
gamy could be obtained among many prothallia, she 
argues that under natural conditions this phenomenon 
is rare in the walking fern and not easily brought about.' 
Vaughan McCaughey has contributed to Torreya an 
account of the ‘“‘pala’’ or mule’s-foot fern (Marattia 
Douglasii,) now the only representative of its family in 
Hawaii, but perhaps the remnant of a once much more 
numerous marattiaceous flora. The species in question, 
abundant in the mountains, is a small tree-fern with a 
short trunk 1-2 ft. high and very large wide-spreading 
fronds. It is remarkable for the fleshy stipules at the 
base of the leaves, which remain adherent to the trunk 
and living even after the leaf has fallen. They are 
starchy and mucilaginous, were used as an article of food 
by the primitive Hawaiians and are said to be highly 
palatable when baked. ‘‘Mule’s-foot fern’ is Mr. Mec- 
Caughey’s own suggestion for an English name for this 
fern. Its appropriateness lies in the fact that the ‘‘en- 
larged leaf-base with the two thick, fleshy stipules curi- 
ously resembles in shape and size” the hoof of a mule.’ 
-1 Brown, Elizabeth Dorothy Wuist, Apogamy in gest quali rhizopiyl- 
lus. Bull. Torr. Bot. Club 46: 27-30, pi. 2. Jan., 1919. 
? MacCa aughey, Vaughan. The pala or mule’s-foot eosgeie Doug- 
ane bedi Baker) in the Hawaiian Archipelago. Torreya -8. Jan. 
