98 GEUM, RUBUS. [CHAP. 



from the position of the anthers probably happens 

 more frequently in the Bird Cherry than in the Black- 

 thorn. The flowers are melliferous. The British 

 species of Spiraea, on the contrary, contain no honey, 

 but are rich in pollen and are consequently visited by 

 insects ; which, from the weakness of the petals, 

 generally alight on the stigma, and thus effect cross- 

 fertilisation ; though the flowers, if not visited by 

 insects, fertilise themselves. Among the foreign 

 species of this genus, several are melliferous. 



Both our English species of Geum (G. rivale and 

 G. urbanunt) are melliferous : but the flowers of G. 

 rivale are much larger than those of G. urbanum, and 

 more frequently visited by insects. Miiller mentions 

 that Primula elatior is deserted by bees as soon as 

 Geum rivale comes into flower. Van Tieghem states 

 that while G. urbanum produces honey in the north, 

 this is not the case in France, at least, near Paris. 



The genus Rubus is very variable, and there are 

 great differences of opinion among botanists as to the 

 specific limits, and the number of species. Bentham 

 admits five, though even these, he adds, "will very 

 frequently be found to pass imperceptibly one into 

 the other." The Raspberry (Rubus idaus) is so called 

 because it is said to be very frequent on Mount Ida, 

 where in 1872 Mr. (now Sir M. E.) Grant Duff and I 

 found in abundance a species, which if not identical with, 

 was very near, our R. idczus. This species, though it 

 secretes honey, is not apparently a great favourite with 

 insects, and frequently fertilises itself. The flowers of 

 the Blackberry (R.fruticosus\ on the contrary, are much 

 more conspicuous, and the stamens are turned more out- 

 wards, so as to leave more room between themselves 



