55 



Love has also been named Volubile, from its twining habit. 

 Its full botanical name is therefore Comesperma volubile. 



The gen vis Comesperma is also strictly Australian, but 

 the family to which it belongs, namely, the Polygala or 

 Milkwort family, is of worldwide distribution. 



We have three or four other Comespermas. The pret- 

 tiest is Purple Broom. It is not a Broom, and it is not 

 purple ; but it is a very pretty shrub for all that, with 

 numerous dark-pink flowers, reminding one at a distance 

 of Native Indigo. There are also two insignificant little 

 forms found in heathy country. These plants are evi- 

 dently structured for insect fertilisation ; probably by 

 hover flies and small beetles. There is a large field of 

 observation awaiting an enthusiast who will patiently 

 study the habits of insects visiting our native flowers. 

 It is very instructive to note the contrivances to insure 

 the ovules being fertilised by pollen brought from another 

 flower. The simplest measure is for pollen and ovules to 

 be produced only on separate blooms. We have noticed 

 this in Clematis and Manuka ; it is much more distinctly 

 the case in Sheoak. A more common way is for pollen and 

 stigma not to mature at the same time. In Lobelia, 

 Trigger Plant. Daisy, and a host of others the pollen is 

 shed some time before the stigma is receptive. In Plantain 

 or Ribgrass the stigma has passed its effective stage, and 

 shrivelled before the anthers are matui'e. Another manner 

 is for the anthers and stigma to be so placed that the 

 pollen cannot get on the stigma by any ordinary means ; 

 this occurs in Violet, Iris, and Orchids. As a last method 

 we may note that for some unexplained reason pollen may 

 be incapable of effectively fertilising the ovules of its 

 flower. It is possible this is the case with Gum and Wat- 

 tle, but has not been enquired into. 



Now, it is very apparent cross- fertilisation must be of 

 great value to plants, or how would all these measures to 

 ensure it have developed ? They are not a meaningless 

 lot of developments that can be classed amongst the acci- 

 dental, for they have a well-marked purpose. Crossing 

 produces more and better seed. Under unusual circum- 

 stances it may be responsible for variation by the produc- 

 tion of seed from rather unlike parents ; but under free 

 and unrestricted crossing it can only have the effect- of 

 breeding out the unusual, and keeping the species oscillat- 

 ing about the mean. It will then be an effective means of 

 suppressing variation and keeping the race close to a type. 



