3IO L. R- CLEVELAND. 



cellulose) seems to reside in the protozoa of the termites rather 

 than in the termites themselves. 



In the present paper the protozoa have been removed from the 

 large Pacific Coast termite, Termopsis, by two other methods, 

 namely, starvation, and oxygenation, with the same results in 

 each case as were obtained by incubation ; the termites were not 

 injured although the ability to live on wood disappeared simul- 

 taneously with the loss of the protozoa. 



In addition to this, the relation of each species of protozoa to 

 its host and to its neighbors or fellow protozoa, has been worked 

 out by employing the various protozoal-removing methods sepa- 

 rately and by combining them. Differential defaunation or the 

 removal of some species of protozoa without affecting the others 

 was thus attained. 



Termopsis AND ITS PROTOZOA. 



Three species of Termopsis are known. Two of them, T. 

 angusticollis Hagen and T. nevadensis Hagen, can be distinguished 

 only by an examination of their winged adults. In many of the 

 colonies studied, no winged adults have appeared; consequently 

 it has been impossible to determine whether all the experiments 

 were carried out on one or both of these species. The winged 

 adults which appeared in two colonies were T. nevadensis. Both 

 species occur in the same localities in Oregon, California and 

 elsewhere on the Pacific Coast and probably harbor an identical 

 protozoan fauna. 1 But for these reasons, it seems most feasible 

 to avoid specific determinations in this paper. 1 



The protozoa of Termopsis were first described by Kofoid and 

 Swezy ('19) as follows: " In Termopsis angusticollis four different 

 species of protozoans are invariably present." These they de- 

 scribed as Trichonympha campanula (Fig. i), Leidyopsis sphaenca 

 (Fig. 2), Trichomitns termitidis (Fig. 3), and Streblomastix strix 

 (Fig. 4). They state that "in addition to these there are usually 

 present minute forms of two, sometimes three species of flagel- 

 lates," which these authors did not study. These same small 

 forms have been observed by the writer, but they are very small 

 indeed, and few in number, and have been considered of no 

 moment in the experiments that have been carried out. 



1 Later observations show that both species were used and that they harbor the 

 same protozoa. 



