ants' nests. 497 



labyrinths. It remains surprising enough, in spite of Treub's later 

 explanation, that so small a plant forms such a colossal bulb, with such 

 cavities, to which a particular species of ant has so evidently adapted 

 itself. It seems to me that the i^ossibility of an adaptation on the part 

 of the plant can not yet be decisively denied, and that we should await 

 further investigations into the biology of Iridomyrmex cordatns and 

 Cremastogaster deformis. The fact that in the botanical garden at 

 Buitenzorg Myrraecodia thrives without Iridomyrmex (Treub) proves 

 nothing, because, in the first place, the conditions of the struggle for 

 existence are entirely different there from those of the primeval forest; 

 and, in the second place, because other ants frequently take possession 

 of tlieir dwellings in the Myrmecodia bulbs, aud act as their represen- 

 tatives. Treub found no dangerous foes of JMyrmecodia in the botanical 

 garden, but in the forest it can be eaten or otherwise destroyed by 

 mammals or other animals which are kept at a distance by the ants. 

 Skepticism is necessary and good, but denial and rejection are not 

 good without sufficient reasons. 



In a shrub in Borneo, Clerodendron Jistulosian Beocart, Beccari 

 constantly found a Colohopsis, whicli Emery has named Gidobopsis 

 clerodcndri. Here the plant, which, like the Ceeropia, has hollow inter- 

 nodes, likewise forms a round attenuated spot in its walls, which is 

 bored through by Colohopsis, and serves it as a door. The ])lant also 

 possesses innumerable extrafloral nectaries (that is to say, glands pro- 

 ducing a sugary liquid, which lie, not in the flowers, but in other 

 places). Still, I am not yet entirely convinced, in this case, that there 

 is an adaptation on the part of the idant, because the species of the 

 genus Colohopsis, so far as hitherto known, are shy and cowardly, and 

 would, consequently, furnish no protectors to the plant. The similar- 

 ity of the shape of the head of the soldier of this species seems to me 

 to indicate that he stops up the round opening of the nest in the stalk 

 of the Clerodendron, with his head, in the same manner that the 

 soldier of our European Colohopsis truncata stops up the door of his 

 wood nest. All investigations on this subject, as well as on the ant's 

 mode of feeding, are stilf wanting. 



There are, besides, a number of similar incomplete or doubtful rela- 

 tions, noticed esijecially by Beccari, as, for example, that of the i>alms 

 of the genus Korthalsia to Componotus liospcs Emery and korthdlsicv 

 Emery; that of plants of the genus Triplaris to various ants which 

 inhabit their stalks, etc.; but minute investigations of them are still 

 wanting. The future will yet bring us many surprises. 



(c) Casual relations. — We have already become acquainted with these 

 in that kind of nest in which the ants make use of natural cavities. 

 Hollow acacia thorns are also frequently used as dwellings by ants 

 which elsewhere make their nests in an entirely different way. Thus, 

 Mr. Wronghton once, in an excei)tiona.l case in India, found Sima nigra 

 Jerdon living in an acacia thorn. 

 SM 94 32 



