64 Flowers and their Unbidden Guests. 



insects ; and yet the nectar of Cwphm micropetala 

 must have some special attraction for ants ; for in no 

 other plant have I ever found so many of them fall 

 victims to the viscid secretion, which they elsewhere 

 avoid with the greatest care, as in this.^ The coroUa- 

 tube, moreover, is so wide, being 4-5 mm. in diameter 

 in its narrowest part, that most of the smaller kinds of 

 ants could get along the sides of the ovary to the 

 mouths of the nectar-passages with perfect ease. Such 

 access, however, to the interior of the flowers is ren- 

 dered impossible, not only to ants, but to all creeping 

 insects, by the following very curious arrangement : — 

 Eound the margin of the calyx, and above the stunted 

 petals, certain knob-shaped epiblastemes stand out, 

 each provided with six or seven somewhat diverging 

 glandular trichomes, which secrete an abundance 

 of viscid matter, and may be aptly compared with 

 lime-twigs. (Plate I. fig. 26.) These Hme-twigs crown 

 the margin of the calyx-tube, and collectively form a 

 " weel," on which no ant that creeps up from the base 

 of the calyx can step without being irretrievably lost. 

 Such flying insects, on the other hand, as remain hover- 

 ing in front of the flower while sucking the nectar, as 

 also such smaller flying species as use the anthers, 

 which project beyond the margin of the calyx (Plate I. 

 fig. 27), for a landing-place, are in no wise hampered by 



* I once found three specimens of Lasim niger firmly glued to a 

 single flower. 



