( 154) 



investigation and among others put myself the following questions 

 to which the here briefly mentioned answei'S were obtained : 



1. On what parts of plants is extrafloral secretion of sugar found ? 

 In the cases examined by me I found secretion of sugar on the 



branches, leaves, stipules, bracts of different kind, peduncles and 

 pedicels, ovaries and the inner and outer side of calyx and corolla, 

 in each of these organs separately or in a great number of different 

 combinations. The most commonly occurring of these combinations 

 were: a. on leaf-sheaths and calyx together, b. on the leaf-blade only 

 c. on the leaf-stalks, peduncle and calyx. Of other combinations I 

 only found from one to three examples each. 



2. Does the structure or place of the nectaries clearly indicate 

 that they are made for receiving ants? 



Except in a few cases (as the nectaries occurring in the closely 

 assembled flowers of Gmellna asiatka SchefF. on that side of the 

 calyx, that is turned away from the axis of the inflorescence) this 

 question must be decidedly answered negatively. Although it seems 

 as if the very common cup shape of the nectaries were eminently 

 suitable for storing the secreted honey, yet on the lower side of the 

 leaves these nectaries are for the greater part found with their 

 opening turned downward. I remind the reader of the two large, 

 also downwardly directed cui)-shaped nectaries at the base of the 

 side leaves of some species of Erythrina. 



The frequent occurrence of nectaries on the calyces, which only 

 in the budding period secrete honey, seems to indicate that these 

 buds require special protection. But inconsistent with this view is 

 the fact that sometimes, according to my observations, only half of 

 the flowers has nectaries in the calyces (e.g. Spathodea campanulata 



Beau v.). 



With many species of Smilax only part; of the branches attracts 

 ants and these are branches that carry no flowers and so, according 

 to the prevailing conception, would least require protection. It is 

 difficult to make the idea of the protection of the flowers agree with 

 the fact that nectaries occur on the inner and outer side of the upper 

 edge of the tube of the corolla oï Nycticalos inacrosyplion, Spathodea 

 serridata and others. Attracting ants to the entrance of the corolla, 

 which is the very place where the animals causing cross-fertilisation 

 have to enter, has certainly to be called unpractical from the biolo- 

 gist's point of view. 



Against the conception that these plants should require protection, 

 also the fact pleads that exactly with young plants, where protection 

 would be most necessary, these baits for protective ants are absent. 



