2l6 L. R. CLEVELAND. 



means of the attachment apparatus it is thus enabled to maintain 

 its position in the intestine in the complex struggle for existence 

 among the many species of protozoa which completely fill the 

 lumen of the termite's intestine. No doubt Pyrsonympha, Tri- 

 chonympha and others, die by the hundreds daily, and thus give 

 over to their host many substances which they have obtained 

 from the wood particles. That they give sugars, 1 such as xylose, 

 may be shown by testing with phloroglucinol and hydrochloric 

 acid. But it is not the intention of the writer to show in this 

 paper the relation of each species of protozoa to its host. Not all 

 of the protozoa harbored by the two hosts, Termopsis and 

 Reticulitermes, have been mentioned, and the protozoa of other 

 termite genera have not been mentioned at all. In a later paper 

 this question will be considered in more detail. 



Unwilling to conclude definitely that the protozoa were entirely 

 responsible for the digestion of cellulose, the other microorganisms 

 harbored by Reticulitermes flavipes were studied. Bacteria were 

 sometimes numerous, and these were studied in many ways. In- 

 cubation at 36 C. for 24 hours does not seem to affect their 

 numbers. All the known methods, aerobic and anaerobic, for 

 isolating cellulose decomposing bacteria were given more than 

 fifty trials, but, since the results of all these experiments were 

 negative, no tabulation has been made. An inorganic medium 

 composed of 



K 2 HPO 4 i .00 gram 



MgSO 4 0.50 " 



KC1 0.50 " 



FeSO 4 o.oi " 



NaNO 3 2.00 " 



H 2 O 1000.00 cc. 



to which cellulose was added in two forms: a small piece of 

 Whatman's filter paper was placed in the test-tubes containing 

 the inorganic medium and a 0.5 per cent, cellulose suspension 

 was added to the inorganic medium. This was sterilized in the 

 usual way and the inoculations made. Then the cellulose sus- 

 pension and inorganic medium plus agar sufficient to make a 



1 Provided the conclusions of Buscalioni and Comes (1910) regarding the phloro- 

 glucinol reaction are accepted. For a discussion of this reaction see page 205-6. 



