J^ 



134 The Irish Naturalist, July, 



All the species mentioned above grow in the neighbourhood 

 on Howth Head. It is worthy of note that eight species were 

 Grasses, and seven species were Composites, these two families 

 being the most successful in colonizing the earth's surface 

 generall}'. 



The two species of Mosses had their spores carried b}^ wind. 

 Nineteen species of Seed Plants were also^ doubtless, distributed 

 in the same waj^, namel}', 8 species of Grasses, i species of 

 Carex, i species of Rumex, 2 species of Epilobium, and 7 

 species of Composites. 



One species, namely, Ritbus Jfuticosus, doubtless had its 

 seeds carried b}' the agency of birds. 



It is somewhat of an enigma how the seeds of the other seven 

 species got there. With the exception of Ulex curopceiis and 

 Icucrium Scorodonia they have verj^ small seeds, which might 

 conceivably be carried by wind. But this method of transport 

 could scarcely be applicable in the case of Whin, which has 

 comparatively^ heavy seeds. Could these by any possibility 

 have survived the fire ? 



It remains to add that the most abundant species on the 

 area under consideration were Ulex europcsus^ Erica cinerea, 

 and Senecio sylvaticiis. 



An interesting reference to a similar subject will be found 

 in Treub's paper. ■• 



Three years after the eruption he found six species of Blue- 

 green Algse, two species of Mosses, eleven species of Ferns, 

 and fifteen species of Seed Plants, four of the last group being 

 Composites. The nearest land in this case was ten miles 

 distant. 



^ " Oil the New Flora of Krakatoa." Ann. and Mag. Nat. Hist. vol. iii., 

 (6th sen), 1889. 



Royal College of vScieiice, Dublin. 



