66 PREDATORY PLANTS. [CHAP. 



in Arum (p. 41, ante). The Virginian Swallowwort 

 (Asclepias syriacus), and the Oleander (Nerium olean- 

 der), are also included among those plants which 

 entrap insects by means of their flowers. 



In a paper recently read before the Entomological 

 Society, Mr. J. M. Slater stated that certain gay- 

 coloured flowers are avoided by bees, or, if visited, 

 have an injurious and even fatal effect upon the 

 insects. Among these are the dahlia, passion-flower, 

 crown imperial, and especially the oleander. That 

 the flowers of the dahlia have a. narcotic effect was 

 first pointed out by the Rev. L. Jenyns, who men- 

 tions that bees which visit these flowers are soon 

 seized with a sort of torpor, and often die unless 

 speedily removed. Mr. Jenyns also quotes a writer 

 in the " Gardeners' Chronicle," who pronounces the 

 cultivation of the dahlia incompatible with the suc- 

 cess of the bee-keeper. The passion-flower also 

 stultifies bees, and bees of all kinds avoid the crown 

 imperial and the oleander, for the honey of the latter 

 is fatal to flies. Mr. Slater did not remember ever 

 having seen a butterfly or moth settling on the 

 flowers of this shrub in Hungary or Dalmatia ; and 

 he thinks it important that observers should ascertain 

 whether the above-mentioned phenomena be true, 

 and whether any insects in such cases undertake 

 the functions [of fertilisation] generally exercised by 

 bees, and whether flowers have a similarly noxious 

 or deadly action upon insects. Science Gossip, 1879, 

 p. 164. 



In addition to these plants above named, there is 

 a group of others that is really insectivorous. The 



