L. R. CLKYKI.AXD. 



land, '240). The symbiosis between these insects and their 

 intestinal flagellates has now been clearly demonstrated by three 

 entirely different methods, namely, incubation, starvation, and 

 oxygenation. 



ADDENDA. 



Since this paper went to press sometime ago several additional 

 observations of interest have been made. 



Thirteen colonies of Termopsis nevadensis and six colonies of 

 Termopsis angnsticollis have been obtained. The protozoa in all 

 of these are the same. 



By dry fixation and staining with Wright's stain one and three 

 minutes respectively it has been possible to demonstrate beyond 

 question four anterior flagella on Trichomonas. No organisms 

 with three anterior flagella, the number Trichomitiis is said to 

 possess, have been observed. Hence it is quite probable that 

 Trichomitus does not occur in Termopsis. Another interesting 

 result was obtained by this method of fixation and staining: It 

 was discovered that Streblomastix has only four flagella, instead 

 of six, the number figured by Kofoid and Swezy ('19). The 

 flagella stand out as big red lines which may be counted almost as 

 easily as so many red pencils. Perhaps this method of fixing and 

 staining will prove valuable in determining the flagella number of 

 other protozoa. 



By oxygenating Termopsis at a pressure of 1.5 atmospheres for 

 7 hours it has been possible to remove both Trichomonas and 

 Streblomastix from many, though never all, hosts without seri- 

 ously effecting Trichonympha and Leidyopsis. When termites 

 oxygenated in this way are starved for six days, Trichonympha 

 disappears entirely, thus making it possible to obtain termites 

 with only Leidyopsis. This gives two more protozoal combi- 

 nations, in addition to the five already obtained, viz. termites 

 with Trichonympha and Leidyopsis, and termites with Leidyopsis. 

 It now seems desirable to tabulate all the protozoal combinations; 

 show how they were obtained, and how, if at all, they effect their 

 hosts. 



