242 
Intestinal Protozoa in Termites 
the nymph the intestine is rather slender, but is also almost filled with protozoa. 
In the imago the condition is variable; in some individuals the intestine is 
quite free from protozoa while in others they are present in rather large 
numbers. Regarding the infections of imagines, my experience is not suffi¬ 
ciently extensive, and further investigations are needed. 
The protozoa found in every individual termite are abundant, not only 
in number, but also in species. Almost all the kinds proper to a particular 
species of host are commonly found in every individual of that species. No 
differences are recognizable among the protozoa found in workers, soldiers, 
and nymphs, and all kinds usually occur with equal frequency in the above 
casts. In imagines which contain protozoa, the conditions seem also identical. 
The fact that the protozoa are present with such frequency is probably 
to be explained by the habits of the termites themselves. They live in com¬ 
munities, and, as is well known, eat one another’s faeces. The space in which 
they live is usually dark and moist, so that the faeces must usually remain 
damp, and the protozoa passed out with them, even though not encysted, 
may thus remain alive for some time. It seems probable also that the same 
habits explain the fact that the young termites become heavily infested in 
very early stages of their development. 
As mentioned in the foregoing historical review, the physiological rela¬ 
tionship between these protozoa and their insect hosts is a subject of profound 
interest and great importance. For the consideration of the role played by 
the protozoa in the digestion of wood fibres in the intestine, the habits of 
all termites, both those harbouring protozoa and those free from them, must 
be carefully investigated. 
I may add here a brief note on the habits of the species studied by myself. 
Leucotermes speratus and L. flaviceps, harbouring Trichonympha, Terato- 
nympha, Holomastigotes, Microspironympha, and Pyrsonympha , are species 
doing some damage to wooden structures. These species form irregular 
cavities and burrows under or in rotten boards, timbers, decayed logs, fallen 
trees, and similar material. Coptotermes formosanus , harbouring Pseudo- 
trichonympha, Holomastigotoides, and Spirotrichonympha, is the most de¬ 
structive species in Japan, especially in Formosa. Wooden buildings, furni¬ 
ture, logs, and decayed portions of living trees are severely attacked by this 
species. Odontotermes formosanus , harbouring none of these protozoa, some¬ 
times attacks also timber and trees, though not causing such extensive damage. 
Soft materials, however, such as the stems and roots of sugar cane are often 
destroyed by this species. Capritermes nitobei in which I did not find any of 
the protozoa in question—though my material was not abundant—has similar 
habits to those of Odontotermes. 
The fluid medium chiefly used for the observation of living organisms was 
a 03-04 per cent, solution of sodium chloride. The same fluid was also used 
for diluting the gut contents in the preparation of fixed smears. Observations 
of the living organisms were found most important in studying these forms; 
