IQ2 L. R. CLEVELAND. 



The wood, according to Imms, after being crushed by the 

 mandibles and later by the gizzard, passes rapidly to the hind-gut 

 without undergoing any chemical change. The pyloric valve 

 prevents the readmission of wood particles into the mid-gut. To 

 quote Imms: "On reaching the hind-intestine the wood is in a 

 condition of minute fragments and particles, and the greater 

 bulk of it gradually becomes taken up and absorbed by the numer- 

 ous intestinal protozoa. Within the protoplasm of these organ- 

 isms the woody material undergoes chemical changes, and, when 

 ejected from the bodies of the protozoa, much of it is in a condi- 

 tion capable of being assimilated as food by the host termite. 

 A significant fact is that lignous particles are not subjected to the 

 action of the secretions of the mid-gut." 



Imms further points out that, in his opinion, the experiments 

 of Grassi and Foa (1911), where these authors claim to have kept 

 Kalotermes (species not given, nor is the number of termites) 

 alive and active for several months with all but a few of the in- 

 testinal protozoa killed off by incubation at about 35 C., has 

 no value, for during incubation the termites very probably sub- 

 sisted on the large amount of fecal matter l which had accumu- 

 lated in the jars where they had been kept previous to incubation. 



Imms, then, through an ingenious method of reasoning, reaches 

 the conclusion that the protozoa are symbionts, a conception 

 already reached by Buscalioni and Comes (1910), who claim, by 

 means of various microchemical tests, to have shown that the 

 wood is digested inside the bodies of the protozoa ; and since the 

 protozoa digest the wood, these authors conclude, that they are 

 symbionts. 2 They state that Trichonympha agilis, harbored by 

 Reticulitermes lucifugus, when treated with iodine dissolved in 

 iodide of potassium , gives a characteristic glycogenic reaction in 

 a region near the nucleus, and that this reacting region is sharply 



in these young second form adults had begun to degenerate through disuse in masti- 

 cating wood. It is believed that second form males like the females would have 

 succumbed, without the workers." First form adults, so far as my experience 

 goes, harbor protozoa, but the second forms do not. This probably explains the 

 inability of the second form adults to live without workers, that is in the event the 

 jaw muscles permitted them to eat wood. Of course the protozoa are lost, possibly, 

 because the host docs not eat wood. I have experiments started which I hope will 

 determine this point. 



1 The fecal matter contains sugars and possibly other foods. 



5 A discussion of this may be found on pages 193-4. 



