27 



their own jaws they deepen their cradles, until, at full growth, they 

 slightly exceed the length of the larva when fully extended. The larvae 

 swallow the wood which they excavate but do not digest it. it pa 



w^^mm- 



Fig. 2j. — Gallery of ALoaarthrum mali in maple (originali. 



through the intestines unchanged in cellular texture but cemented by 

 the excrement into x^ellets and stained a yellowish color. The pellets 

 of excrement are not allowed by the larvae to accumulate in their cra- 

 dles, but are frequently ejected by them and are removed and east out 

 of the mouth of the borings by 



the mother beetle. A portion 

 of the excrement is evidently 

 utilized to form the fungus 

 garden bed. The mother 

 beetle is constantly in atten- 

 dance upon her young during 

 the period of their develop- 

 ment, and guards them with 

 jealous care. 



The mouth of each cradle is 

 closed with a plug of the food 

 fungus, and as fast as this is 

 consumed it is renewed with 

 fresh material. The larva 4 from 

 time to time perforate this plug 

 and clean out their cells, push- 

 ing out the pellets of excrement 

 through the opening. This 

 debris is promptly removed 

 by the mother and the opening 

 again sealed with ambrosia. The young transform to perfect beetles 

 before leaving their cradles and emerging into the galleries 



The ambrosia ofMonarthrnm tig. 26) is moniliform, like that of Cor- 

 thylus, and resembles a mass of pearly beads. In its incipient sto 



Fn;. 



J6. — Ambrosia of M marthrum mo K - g reatly en- 

 larged (original). 



