14 MR. H. N. RIDLEY ON THE 



miueral matters in the soil prevent the growth of purely marsh- 

 plants. The dryness of tlie climate is also no doubt the reason 

 for the absence of sylvestral plants, the Sapate woods, where 

 such plants would naturally occur, being dry and rocky. 



Tlie absence of petaloid Monocotyledons from oceanic islands 

 has been commented on by Hemsley, Chall. Exp. Eeport, Bot. 

 vol. i., and Fernando Noronha is no exception to the rule. Plants 

 with winged or feathery seeds are supposed to possess great faci- 

 lities for being widely^dissemiuated. That this is really the ease 

 maybe doubted. The only species with wiuged or plumed seeds 

 here arc Gonolohus micrantJius, Jussieua linifolia, and Ageratum 

 conyzoides. The first of these is endemic; its plumed seeds are used 

 by the endemic Tyrant, Elainea Bidlei/ana, to liue its nest with. 

 Is it conceivable that the seeds of the ancestor of this plant were 

 accidentally brought over attached to the feathers of some bird 

 which had, in like manner, used them for its nest ? Jussieua is 

 a marsh-plant, with small seeds plumed like those of an JEpi- 

 lohium ; it and the Ageratum only occurred in the cultivated 

 ground in the centre of the island. The latter certainly, and 

 possibly the former, were introduced as weeds by man. 



Bromeliaceae, though commonly provided with plumed seeds 

 and abundant in Brazil, are quite absent here. In reality it 

 would require a strong and very long-continued wind to carry 

 plumed seeds to such a distance from the land, and even if such 

 should be the case, the chances of seeds dropping upon a small 

 island like this would be exceedingly remote. 



Jiecent Alterations in the Flora. 

 When the island was first discovered in 1503, Ves^jucci found 

 there infinite numbers of trees, most of which have now dis- 

 appeared. Of Erytlirina exaltata, mentioned by Webster as the 

 largest tree in the island, only one full-sized tree now remains ; 

 and as it seems that the young trees will not flower, the species 

 appears to be threatened with speedy extinction. Of the fig- 

 tree, again, but few large ones remain, the finest being in the 

 Governor's garden. This is due to an order of the govern- 

 ment, which provides that all trees of a sufficient size to be made 

 into rafts shall be destroyed, for fear that the convicts might 

 escape on them ; and besides this the constant demand for fire- 

 wood causes great destruction amongst the smaller shrubs. I 

 could not find, however, from the inhabitants, that any perceptible 



