92 Zoologica: N. Y. Zoological Society [HI; 3 



Picard (1919) has recently published an interesting paper on the 

 insects of the fig in Southern France. 



As a mere record of the insects associated with a tropical 

 plant my study of the Tachigalia biocoenose is necessarily frag- 

 mentary, owing to the few weeks I could devote to it, but it ac- 

 quires considerable interest from the fact that the Tachigalia is a 

 myrmecophyte, or one of those plants which are supposed to be 

 peculiarly adapted structurally to association with battalions of 

 protecting ants. The only organs which can be cited, however, a? 

 such an adaptation are the fusiform enlargements of the petioles, 

 which undoubtedly furnish excellent lodgings for all the various 

 ants, both inquiline and obligate. The plant is utilized also as a 

 source of food by the obligate species through the instrumental- 

 ity of the coccids, which are kept in the petioles and draw their 

 food by preference from the strands of nutritive parenchyma. 

 Thp beetles also use the petioles as lodgings and not only utilize 

 the species of coccid as a copious source of sugar and water but 

 also feed directly on the tissues of the plant. The plant is there- 

 fore more completely exploited by the beetles than by the ants and 

 might be said to be more perfectly adapted to the former than to 

 the latter. But the question as to whether the peculiar structure 

 of the petiole is really an adaptation to either of these groups of 

 insects is one which I shall leave to the botanist. Prof. Bailey 

 will no doubt deal with it in connection with the same problenr 

 in the other South American myrmecophytes which he has inves- 

 tigated. That both the ants and the beetles have adapted them- 

 selves to the plant cannot be doubted and this adaptation, as I 

 have shown, is exhibited in three degrees, the inquiline ants 

 merely using the petiolar enlargements as lodgings, the obligate 

 ants as lodgings and through their herds of coccids as indirect 

 sources of food, and the beetles as lodgings and as both direct 

 and indirect sources of nutriment. 



Of course, a particular biocoenose is not an isolated, per- 

 fectly self-contained association of organisms but shares some 

 of its components with other biocoenoses. Thus the Tachigalia 

 is part of a large association, or biocoenose of jungle trees grow- 

 ing under certain conditions of soil, humidity, light, tempera- 

 ture, etc. The Atta ccphalotes, which occasionally defoliates the 

 young tree is the center of an elaborate biocoenose of its own. 



