456 L. R. CLEVELAND. 



Approximately half the body weight of every worker and nymph, 

 except for a few days after molting, is composed of many kinds of 

 large, intestinal flagellates. Recently molted termites are lacking 

 in pigment and for this reason may easily be distinguished from 

 other individuals. There is no difficulty whatever, then, in being 

 absolutely certain that all animals used in experiments harbor a 

 teeming menagerie of protozoa ; consequently termites lend them- 

 selves most admirably to many kinds of precise experimentation. 



In a previous paper the writer ('256) showed that Trichomonas 

 termopsidis was entirely removed from the large Pacific Coast 

 termite Termopsis nevadensis Hagen after 24 hours' oxygenation 

 at one atmosphere pressure, and that all the other protozoa 

 (Trichonympha campanula, Leidyopsis sphaerica, Streblomastix 

 strix) were removed after 72 hours' oxygenation. The termites 

 suffered no ill-effects per se from the oxygenation, although they 

 died within three to four \veeks after their protozoa had been 

 removed. Recently this work has been carried further: four 

 widely separated species of termites from two families have been 

 used; and various intervals and amounts of pressure have been 

 employed. 



The bearing which these experiments have on the symbiosis be- 

 tween these termites and their intestinal flagellates will be re- 

 served for a later paper. It is sufficient at present to say that 

 the ability of these termites to live on their normal diet of wood 

 is lost after their protozoa have been removed, regardless of the 

 method employed in removing them. 



Many other protozoa-harboring animals, such as cockroaches, 

 earthworms, frogs and rats have been oxygenated. Some of the 

 protozoa of the frog, rat, and man have been grown in cultures 

 which have been oxygenated. And oxygenation experiments 

 have been carried out on several free-living protozoa. 



MATERIAL. 



Of the termite family Rhinotermitidae, Leucotermes tennis 

 Hagen from British Guiana and Reticulitermesflavipes Kollar from 

 Maryland were used; in the family Kalotermitidae, Cryptotermes 

 sp. from British Guiana and Termopsis nevadensis Hagen from 

 Oregon were used. Many thanks are due Dr. Alfred Emerson for 

 Cryptotermes and Leucotermes. 



