i393- ON EPIPHYTES. 181 



galleries is not out of harmony with this view. The observation that 

 under cultivation these plants live without their ants, tells us naught of 

 what would happen to them in their wild state under similar 

 circumstances ; and it is futile to object that the plants cannot be 

 myrmecophilous (ant-loving) because they do not attract ants by 

 means of honey or food. Ants are attracted to these plants. This 

 is proved, first, by the constant presence of a certain definite 

 species of ant in specimens growing wild ; and, secondly, by the 

 extreme difficulty in preventing ants crowding on cultivated seedlings 

 of these plants, even when adjacent seedlings of other plants are 

 neglected. It is possible that ants convey into the galleries materials 

 which can be subsequently utilised by the roots therein. But at 

 present Myrmecodia and Hydnophytum are living mysteries. 



Class II. 



The second class, represented by the Bromeliaceae, stands apart 

 from the types previously described in that food and water are 

 absorbed by the leaves — and not to any appreciable extent by the 

 roots. 



Often the leaves together form a very close rosette — a funnel — 

 which contains water with humus-giving bodies. By isolating some 

 of these funnel-forming bromeliads, Schimper proved that the leaves 

 absorbed nutritive solutions. Living specimens were deprived 

 of their roots and the wounds were closed with Canada balsam. 

 Water was poured into the funnels of some of these, but the rest were 

 kept without water. The former remained fresh as long as the 

 experiment lasted — ten to twelve weeks ; but the latter died in the 

 course of a few days or weeks. Water supplied only to the roots of 

 isolated specimens neither restored faded plants nor appreciably 

 retarded the death of freshly isolated individuals. This experiment 

 shows that the roots absorb only a negligible amount of water — they 

 are purely organs of attachment. Hence epiphytic bromeliads which 

 have other means of fixation are devoid of roots. 



Tillandsia usneoides is one of the commonest rootless Epiphytes 

 belonging to the Bromeliaceae. This plant forms silvery-grey, 

 pendent masses, which resemble horses' tails or manes. These tufts 

 attain lengths of more than ten feet. Each thread consists of a 

 filamentous distichous shoot, which, at its base, twines round a 

 branch of its host. Hanging down as it does, the plant possesses no 

 external, funnel-like reservoir for water. 



The water is absorbed by means of certain peculiar scaly hairs. 

 In funnel-forming bromeliads these are confined to the basal parts of 

 the leaves, thus they only occur in the region of the water-reservoirs ; 

 but in forms, like Tillandsia usneoides, having no external receptacle for 

 water, the scaly hairs are distributed over the whole surface. 



In Tillandsia, which may serve as a type, each scaly hair consists 

 of: (i.) a stalk-like base sunk into the tissue ; (ii.) a peltate upper part 



