Flowering Plants of New Zealand. 99 



" British Wild Flowers in relation to Insects." Such a 

 comparison would not only be interesting, but would 

 enable us to form a more correct estimate of the relative 

 poverty of our flora and insect fauna, as compared with 

 those of other countries. 



Taken as a whole, I think the figures I have given 

 will show that flower-frequenting insects are much more 

 abundant here than is commonly supposed, and that our 

 flowering plants are very largely dependent on their aid 

 for propagation. 



The most remarkable feature to my mind is the fact 

 that the Diptera appear to take the place of and carry out 

 the functions performed by the Hymenoptera in other parts 

 of the world. I cannot find that they are anywhere 

 mentioned as aiding in the pollination of plants, but here 

 many flowers are exclusively dependent on them. Tuidtia 

 antarctica., a mistletoe with small, pale green, very frag- 

 rant flowers ; Corysanthes (3 species), with small purple 

 scentless flowers, always hidden among foliage, and close 

 to the ground ; and Pterostylis (3 species), with large 

 solitary scentless green flowers, belong to this category, 

 which also includes, I believe, the fragrant, dark green, 

 dioecious flowers of Astelia nervosa. It was the attempt 

 to unravel the mode of fertilisation of Tupeia which first 

 induced me to examine into this subject. The plant is a 

 good sized parasite, usually growing in the shelter of the 

 bush (forest), removed from the influence of the wind, and 

 with strictly dioecious flowers, which contain a lot of honey. 

 It is frequented by numbers of very small Diptera, which 

 must be attracted by smell, as the flowers are inconspicu- 

 ous at the distance of a few yards. 



The systematic examination of the questions touched 

 on by me has only been commenced in New Zealand, and 

 this contribution of mine is only intended as a preliminary 

 one. In a paper read before the local Institute — but 

 not published yet — I have gone more into detail on this 

 subject. 



The occurrence of Heteromorphism among our flowers 

 has hardly been noticed yet. The two species of Viola 

 occurring commonly here, viz., V.JlUcauUs and V. Cunning- 

 maii, both produce cleistogamic flowers in abundance, 



