32 
Psyche 
[March 
II 
It was observed that relatively large blocks of tissue 
were present in the faeces of these carnivorous larvae. In 
order to facilitate the examination of these tissues to deter- 
mine what benefit the larvae were deriving from their diet 
the faeces were preserved in alcohol, sectioned in paraffin, 
and stained with Delafield’s hematoxylin and eosin. 
Examination revealed that the tracheae as well as all 
other chitinous structures had passed through the alimen- 
tary canal completely untouched. This was to be expected 
since the occurrence of an enzyme acting upon chitin is very 
limited (Uvarov, 1928). Epithelium had been completely 
broken down. Relatively large blocks of muscle tissue were 
present in the fseces. These were recognizable as such ; but 
digestion had been more or less complete, nothing remaining 
but a faint indication of the muscle fibers. No conclusion 
could be drawn concerning the fate of fat due to the histo- 
logical procedure employed. Plant material from the gut of 
the victim was also present in the fseces. Serial sections 
revealed that cell walls in the majority of cases were intact 
although the entire contents had been removed. This is in 
accord with Biedermann’s (1919) contention that all the 
active components of the digestive juice can diffuse through 
cell membranes. 
In order to throw further light upon the situation, larvse 
were tested for the presence of various digestive enzymes. 
Tests were adapted from Swingle’s (1925), Wigglesworth’s 
(1928), Cole’s (1928), and Feigl’s (1937) techniques. No 
attempt was made to conduct a differential analysis. In- 
vertase and maltase were present. Neither lipase, lactase, 
nor amylase were detected. Amylase had been found occur- 
ring quite commonly, however (Dirks, 1922; Straus, 1909; 
Biedermann, 1911 and 1919). Lactase had been reported 
from some species. Proteases and glycogenase also occur 
(Uvarov, 1928) . It is apparent from the standpoint of the 
enzymes found present by various workers that phytopha- 
gous larvse are capable of digesting a meat diet. That both 
proteases and diastases occur in carnivorous insects and 
phytophagous insects alike is well known. 
As seen by the examination of fseces most of the con- 
stituents of a meat diet were utilized. Furthermore, all the 
