540 THE MONTHLY BULLETIN. 



nests. This fungus at first sends out small projecting stalks on the top 

 of which are swollen bodies full of protoplasm, known as kohi-rabi 

 clump, which are used as the sole food of the ants. These are special- 

 ized bodies that tend to form and then disappear unless the vegetative 

 filaments are kept down. The ants, even the youngest females, care- 

 fully keep the filaments nipped off as they begin to grow so that the 

 fungus will continue to form the kohl-rabi clumps. Contaminating or 

 undesirable mold fungi of many kinds always tend to spring up like 

 weeds and crowd out the desirable fungus. The ants also guard 

 against this and carefully nip off any foreign organisms that show 

 themselves, as a gardener would keep down the weeds in his tomato 

 patch. In this way the ants keep a pure culture of their favorite 

 mushroom. 



Alf. MoUer^ was the first to investigate and prove the truth of this 

 interesting relation between the ants and the fungus. By finding that 

 the fungus at times produced a large mushroom growth above the nests, 

 he was able to identify it as a new species of Bozites {Bozites gongylo- 

 pliora) a form that has never been found except in connection with 

 nests of the parasol ants. 



The damage done by these parasol ants to citrus trees in some trop- 

 ical countries is very great, because of the almost complete stripping 

 off of the leaves in which to grow the spawn for the ants' mushroom 

 cellar. 



It is fortunate that the California fruit grower does not have to 

 supply food for an ant of this nature, 



=Alf. Moller, Botan. Mitthlel. aus den Tropen Heft. VL Jena, 1893. 



