THE FOUNDING OF COLONIES BY ATTA SEXDENS. 359 



It is necessary to state here that the foregoing case of develop- 

 ment in forty days is the most successful one that I have in my record 

 of cultures. However, the majority of cases belonging to the last 

 flight of female ants, which occurred on March 12, are classed to this 

 categor3^ Some few of these were, together with their offspring, 

 very slow in development, and some of the broods required a period of 

 two months and three days before the first working ant appeared and 

 became active. 



These, in a general way, are the facts observed in a preliminary 

 study of the founding of a new colony by Atta s"xdens. But there are 

 a number of questions, answers to which are imperative for the bi- 

 ologist, and the solving of which becomes possible only by very critical 

 observation. These problems are the fertilizing of the fungus garden 

 and the nourishment of the mother ant and her young brood. 



The question of chief moment is this: What means are employed 

 by the queen ant to stimulate and maintain the growth of the fungus 

 ])rought by her in the cavity at the back of the mouth? For this 

 organic source of supply needs to be developed in the shortest pos- 

 sible time, and it is evidently out of the question to suppose that a 

 pellet of fungus hardly 0.5 mm. in diameter can be made to grow into 

 a fungus garden of more than 2 cm. in diameter and bear its fruitage 

 of kohlrabi without some special means of nourishing. A micro- 

 scopical examination of a young fungus garden reveals a meager sub- 

 stratum of plant material recognizable as fragments of plant epi- 

 dermis, vascular tubes, corroded starch grains, and crystals of oxalate 

 of lime. But these substances are to be found in like proportion in 

 the original fungus pellet, and it is evident they were transported 

 with it from the mother colon^^ In addition to these materials there 

 are soon seen to be among the fungus masses torn fragments placed 

 here and there and saturated with a yellowish liquid, and even without 

 the aid of a lens yellow areas and yellow or brown drops are discov- 

 erable. These drops are the key to the puzzle as to the mode of 

 nourishing the young fungus garden," There is no doubt as to the 

 fact of this manuring of the fungus by the ant with liquid excreta. 

 The further cultivation of the garden consists in licking the threads 

 (hypha?), a process that hardly tends to promote growth, but rather 

 serves to control and guide it in certain directions. The operation is 

 also an agreeable one for the ant, as certain transparent drops are 

 exuded from the fungus which she consumes. The development of 

 the new fungus garden is therefore seen to be essentially a matter of 

 its enrichment by means of excreta, and the granular or flecked 

 appearance of the fungus, as well as the constant increase in the num- 



"The author at this point enters into a detailed and unreserved description of 

 manuring tlie fungus beds by tlie female Atta by the use of excreta of her own 

 body. A literal translation of this passage is here omitted. — Translatoi*. 



