Campbell's Islands.] FLOEA ANTARCTICA. 107 



upper regions forming small tufts of the ordinary mode of growth in ferns. Besides these variations in size and 

 luxuriance, depending wholly upon climate, I find that the pinna? and pinnules are more or less remote, with longer 

 or shorter apices, and the segments of the latter are either decidedly rounded and blunt, or all acuminated and 

 pungent ; in general, however, the lower segments are obtuse and the upper acute. As a species it is abundantly 

 distinct from A. proliferum, Br., in the presence of the large palese. In New Zealand it is probably even a more 

 sportive plant than iu the islands now under consideration, for I am inclined to refer to it Mr. Colenso's A. TFaikar- 

 eme, A. sylvaticiim, and A. pulcherrimum. 



The islands of New Zealand have long been known to produce a very large proportion of Ferns compared to their 

 phaenogamic plants ; a circumstance which must strike the most casual observer. Being an attractive branch of Botany, 

 it might be supposed that the excess of this Natural Order was rather apparent than real, and only due to its species 

 being more generally collected and transmitted to England : but this is not wholly the case, the exertions of 

 recent collectors having increased this proportion, to what is probably the maximum; for being more widely 

 distributed than the higher orders, the hitherto partially explored middle island may be expected to produce new 

 forms of flowering plants, accompanied with a large number of Ferns it is true, but those of species already 

 detected elsewhere. The species of widely spread natural orders, being very frequently themselves distributed 

 over large areas, it follows that the relative amount which such bear to the remainder of the vegetable kingdom, 

 in a country so large as New Zealand, cannot be ascertained from an examination of the productions of one half 

 of its area only. Mr. Brown has stated (Expedition to Congo, App. p. 462) the conditions which appear most 

 requisite for the abundant production of Ferns, and these are to a great extent amply fulfilled in the position and 

 climate of New Zealand ; for not only the number of species is great, but the mode of growth of many is indicative of 

 a lower latitude than they inhabit, no less than six assuming the arborescent form, one of which attains the 47 th 

 degree of south latitude : besides this, other species, whose stipites spring from the root at once, become caules- 

 cent, having their fronds disposed on the apex of the caudex, as those of the true tree-ferns are, giving a totally 

 different, as well as far more beautiful habit to the plant. Of this there are a few examples in New Zealand, as 

 the Aspidium pennigeriim and several species of Lomaria, and a more striking one in the Asp. venustum, which 

 presents this unexpected appearance in the high latitude (for these regions) of the 53rd degree, and is wholly due 

 to the shade, moisture, and equable climate of the sea-level in Lord Auckland's group and Campbell's Island ; 

 for on ascending the hills, or even leaving the woods, this fern assumes the ordinary appearance of other Aspidia. 



Although the most abundant production of Ferns is found under the physical features of shade, moisture, and 

 a certain amount of heat, these are not on the one hand always present where the Ferns do preponderate to a great 

 degree, nor on the other do the latter always appear where these conditions are the most evident. 



The small island of St. Helena has its Flora composed of nearly equal portions of Pluenogamic plants, 

 Ferns, and other Cryptogamiae, the Ferns forming about a third part of the whole, and nearly equalling the flowering 

 plants ; this is only to be expected from St. Helena fulfilling the above conditions in a most eminent degree. The 

 little island of Ascension, on the other hand, about 500 miles distant, is proverbially called a cinder, with hardly 

 water sufficient to supply a garrison composed of a mere handful of men, and absolutely but one small drip, rather 

 than spring, in the whole island, supplied by the percolation of condensed sea-vapours on the narrow top of a 

 hill, 2818 feet high; no shade exists any where, and the soil is porous volcanic scoria?, that scorches the feet after 

 being heated by a tropical sun ; under all these circumstances it produces likewise as many Ferns as native flower- 

 ing plants. It is true that they are confined to the top of Green Mountain, whose slopes in many places are 

 completely covered by them, but they enjoy no shade, the only native woody plant not attaining two feet in 

 height ; and what is more remarkable, out of nine species of Ferns existing under these circumstances, only two 

 are common to Ascension Island and St. Helena ; several are peculiar to their isolated position, and one is a 

 species of Mara/da, a genus I believe to be in general particularly impatient of exposure. I kuow no parallel 

 instance to this amongst the Atlantic islands ; a far larger proportion of the ferns, both of St. Helena and of 

 Tristan d'Acunha, is common to both these spots, and to other parts of the globe, than are those of Ascension ; 



