ENDOTHIA PIGMENTS 
different pigments are elaborated by the fungi in this genus. It has 
been shown further that the curves of the percentage of spectral 
transmission of the acidified alcoholic extracts of the pigments from 
the seven different fungi group themselves into three distinct classes. 
An investigation of the pigments produced by typical fungi from each 
of these three classes, i. e., E. parasitica, E. fluens, and E. tropicalis, 
show that there is one pigment common to all three groups but that 
each of the three fungi is characterized by some one of the three pig- 
ments. 
E. tropicalis apparently elaborates only pigment A in quantity, 
although a very little of pigment C may be present. E. parasitica, 
the type of the group which contains also E. longirostris and E. fluens 
mississippiensis, secretes pigment A in srriall amounts, but pigment 
B was not found at all. Pigment C is characteristic of this group. 
The group containing E. fluens, E. gyrosa, and E. singularis, of which 
E. fluens is considered typical, is apparently the only one of the three 
which secretes all the pigments. Pigment B is found only in this 
group, and is thus characteristic of the group. This pigment is soluble 
in water and is the cause of the "perilla purple" color in cultures of 
this fungus. It frequently forms crystals on the mycelium (fig. 6). 
It is evident from this work that the curves of percentage of 
spectral transmission shown in figures i to 5 are in most cases curves 
of mixtures of these pigments, and that the difference in the curves of 
spectral transmission for the three groups is due to the fact that differ- 
ent pigments predominate in the alcoholic extracts from the fungi of 
these three groups. It is probable that further investigation with 
quantitative methods would show that the variation in the curves for 
different members of the same group was due to the presence in varying 
proportions of the pigments characteristic of that group. 
It is of interest to note that the grouping of the species based on 
the spectral transmission of the acidified alcoholic extracts of the 
mycelium shows no apparent agreement with the division based on 
morphology, host, or geographical distribution. E. tropicalis, which 
apparently produces only pigment A, differs to be sure from all the 
other fungi examined in host and geographical distribution, being 
known only from Ceylon on Elaeocarpus. It is, however, rather 
closely related morphologically to E. parasitica and other members of 
this group. 
The group characterized by a curve of spectral transmission in- 
