GERANIACE^ 



125 



The large -flowered species are protandrous, the inner row 

 of stamens generally opening first. The flowers are 

 much visited by insects and dependent on them for 

 fertilisation. The species with smaller flowers are less 

 visited by insects and less dependent on them. Honey 

 is richly secreted by five nectaries, generally at the 

 outer side of the base of the inner stamens. It is 

 protected from rain and from creeping insects by a 

 number of fine hairs just above the base of the petals. 

 The presence of these hairs on 

 the petals of G. sylvaticum 

 started Sprengel on his clas- 

 sical study of flowers. He 

 argued that the great Creator 

 would have made nothing in 

 vain, and therefore that even 

 these tiny hairs must be of 

 some use. 



In the large-flowered 

 species, as, for instance, in G. 

 pratense (Figs. 69, 70), all 

 the stamens open, shed their 

 pollen, and wither away before 

 the pistil comes to maturity. 

 The flower cannot therefore 

 fertilise itself, and depends 

 entirely on the visits of insects 

 for the transference of the pollen. In G. pyrenaicum, 

 where the flower is not quite so large, all the stamens 

 ripen before the stigma, but the interval is shorter, and the 

 stigma is mature before all the anthers have shed their 

 pollen. It is therefore not absolutely dependent on 

 insects. In G. molle, which has a still smaller flower, 

 five of the stamens come to maturity before the stigma, 

 but the last five ripen simultaneously with it. Lastly, 

 in G. pusillum, which is least of all, the stigma ripens 

 even before the stamens. Thus, then, we have a series 

 more or less dependent on insects, from G. pratense, 

 to which they are necessary, to G. pusillum, which is 



Fig. 69. — Geranium pratense. 



