314 BOTANICAL GAZETTE [october 



proceeds through the living substance. The paper maintains the high standard 

 we have come to expect from this author. — Raymond H. Pond. 



Ants and plants. — Ule has already smitten hard the theory of myrmecoph- 

 ily, according to which the complicated cavities and other structures have arisen 

 by natural selection through the protection afforded by the sjTnbiotic ants against 

 injury by other ants and browsing animals. Now he concludes^ that it must be 

 given up almost entirely, because his more extended observations in the Amazon 

 region, where such plants most do congregate, cannot be reconciled with the 

 theory. 



The ant plants grow most abundantly in flooded regions, where no leaf -cutting 

 ants are found; the devastation by leaf-cutters is not so extensive as it has been 

 reckoned by von Ihering; the weapons of the protective ants are not efficient, 

 especially against thick-skinned animals, and are not capable of such wounds as 

 those of many other ants; and the protection afforded, while possibly advantageous 

 in the struggle for existence, is not sufficient to call forth the elaborate cavities and 

 other "adaptive" structures. In explanation of the symbiosis, Ule would rather 

 lay stress upon the initiative of the ants, which chose aptly the plants that suited 

 their needs, and perhaps have modified them by the intimate and constant symbiosiS| 

 in much the same way as man has improved the wild ancestors of his useful plants. 

 But the cavities must have originated through deeper-lying causes. 



Amazon 



mimi 



nosae and Moraceae each 7. 



erures 



bif: 



sacs and incidentally as dwellings for Azteca Traili. 



A still more vigorous objection is made by von Ihering, ^° who has studied 

 the relations between Cecropia adenopus Mart, and its inhabitant, Azteca Muelleri 

 Emer}% in a much more thorough fashion than was done by Fritz Mueller and 

 ScHiiiPER. He has given special attention to the life-history of the ants and 

 the metamorphosis of their nests. The ''MuUerian bodies," which grow on the 

 leaf bases, are not used to feed the larvae but as food by the ants themselves, 

 though they are by no means restricted thereto. The small tumors, produced from 



.Tna 



gnawmg the prostoma open, contain sugary and fatty substances and serve as 

 food. Von Ihering rejects absolutely the elaborate conceptions of ''mutualism" 

 and "myrmecophily, " and declares in so many words that Cecropia adenopus can 

 get along quite as well without ants as a dog can without fleas. He considers the 

 ants mere parasites, completely adapted to this plant, without which they cannot 

 prosper at all; but all the plant "adaptations" are like those that hosts everj'- 

 where show to parasites. — C. R, B. 



9 Ule, E., Ameisenpflanzen. Engler's Bot. Jahrb. 37:335-352.^^^.5, 6. 1906. 



10 Ihering, H. von, Die Cecropien und ihre Schutzameisen. Engler's Bot. 

 Jahrb. 39:666-714. fig, /. pis. 6~io. 1907. 



I 



