ANTS AND PLANTS 189 



and has noted that the first galleries, at any rate, are 

 produced by a mere breaking down of tissue without 

 the help of ants at all, whilst tubers transported from 

 the jungle to the botanical garden were often entirely 

 deserted by ants and yet flourished well, putting out 

 new leaves, producing flowers and seed. In opposi- 

 tion to Beccari, Treub considers that not only the 

 tubers, but the galleries in them, are part of the normal 

 development of the plant, the galleries serving for 

 aeration. The ants he regards as mere opportunists 

 who have taken advantage of the conveniently galleried 

 tubers to make their home there. The ingenuity of 

 Beccari's arguments is matched by the uncompromis- 

 ing clarity of Treub's observations and experiments. 

 When the seed of Myrmecodia germinates, the hypo- 

 cotylar axis, i.e. the part of the seedling underneath 

 the two first leaves or cotyledons, begins to swell and 

 continues to grow until a little tuber is formed, and 

 later, when the seedling has become a plantlet, a hole 

 appears leading from the exterior into the tuber, which 

 is now hollowed : this is the first gallery. If a cross- 

 section of a developing tuber be cut, it will be seen 

 that it is made up of large thin-walled cells, called paren- 

 chyma, and in the middle is a single vascular bundle. 

 Later on, other peripheral vascular bundles appear, 

 and then arises around the central bundle a ring of 

 different cells termed meristem a ring within which 

 all the cells dry up and become flocculent, so that a 

 cavity, the first gallery, is formed. The meristem, 

 seen as a ring in cross-section, is really a cylinder of 

 cells, conical towards the tip of the little tuber, but 

 at its base abutting on the outer cork-layer, which 

 spontaneously breaks down, and so the first opening is 



