190 
CHRIST. 
Dryopteris, in spite of the sacrifice of personal opinions and in spite 
of being obliged to discard names that have been in constant use for a 
century anJ" which are known to all botanists. 
;N"owhere else is the type of Nephrodium with anastomosing veins so 
diversified as in the Philippines. There are in the Philippines forms 
with very narrow pinna3, and some special characters are found in the 
species of this region more often than in those of other parts of the 
world. These cliaracters are: Pinnae attenuated toward their bases, 
the lower ones dcficxed, the pinnae degenerating into auricles at the base 
of the frond, sometimes abruptly, sometimes gradually. In other equa- 
torial regions species with these characters are rather rare. In tropical 
America, Dryopteris sagiitaia (Sw.) is almost the only known species 
of the group where the frond is abruptly reduced at the base, the lower 
pinnae being represented by auricles, and D. refracta (Fisch. & Mey.) 
is one of the rare examples of a species with deflexed pinnte. The Ma- 
layan region offers the most frequent examples of species presenting 
the two last characters, for example D. sa^iUifolia (Bhrnie) of Java, 
but even in the Malayan region such species do not approach in number 
tliosc of the Philippines. 
Tliere is in the Philippines a tendency to "insular'^ reduced types 
which is rather interesting. These reduced types elsewhere are rare, 
and abnormal. The irregularity and reduction of the fronds and even 
the dimorphism of the fertile fronds is normal in Dryopteris canescens 
(Blume) as found in the Philippines, and Z>. glandulosa has analogous 
tendencies. These variations do not as yet appear to be constant, and 
they offer sorae subspecies and varieties of doubtftd value, which are 
discussed later under the two above species. In the Archipelago more- 
over are analogous variations in other genera, for example the singularly 
stunted forms that are grouped under Leptocliilns hcterocUtus (Presl) 
{Acrostichum ftagelUferum Wall.), and some species of Pteris, such as 
P. ensifonnis Burm., and P. heteromorpJia Pee. In the West Indies, 
Cuba, Jamaica, Porto Eico, Santo Domingo, etc., analogous insular forms 
are found in Polystichum, Fadyenia, Sagenia and especially in Dryopteris 
reptans (Cmel.) which there offer multiple reduced forms. I am sure 
that the very prolonged isolation of these archipelagoes plays some role 
in the occurrence of these variations, althougli it is not possible at present 
to specify just what this influence is. 
The wonderful variations of Dryopteris canescens^ which are found 
in other parts of Malaya (Celebes) only as rarities, but which are 
developed in the Philippines Into a bewildering series of forms, appear 
to me to throw some new light on the ^^aberrant forms" of the old 
school of pteridologists. By the variations of Dryopteris canescens^ 
which present an unbroken and insensible transition from a true l^eph- 
Todium to a plant entirely achrostichoid as to the sori, the afTmity of 
r 
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