494 



ISLAND LIFE. 



[part it. 



Madagascar and the Antilles, by the preservation in these 

 localities of remnants of once wide-spread types, so we should 

 prefer to consider the few genera common to Australia and 

 South Africa as remnants of an ancient vegetation, once spread 

 over the northern hemisphere, driven southward by the pressure 

 of more specialised types, and now finding a refuge in these 

 two widely separated southern lands. It is suggestive of such 

 an explanation that these genera are either of very ancient 

 groups— as Conifers and Cycads — or plants of low organisation 

 as the Eestiacese — or of world-wide distribution, as Melan- 

 thacese. 



The Endemic Genera of Plants in New Zealand. — Ke turning 

 now to the New Zealand flora, with which we are more espe- 

 cially concerned, there only remains to be considered the pecu- 

 liar or endemic genera which characterise it. These are thirty- 

 two in number, and are mostly very isolated. A few have 

 affinities with Arctic groups, others with Himalayan, or 

 Australian genera ; several are tropical forms, but the majority 

 appear to be altogether peculiar types of world-wide groups — as 

 Leguminos^, Saxifragese, Compositse, Orchidese, &c. We must 

 evidently trace ba^k these peculiar forms to the earliest immi- 

 grants, either from the north or from the south ; and the great 

 antiquity we are obliged to give to New Zealand — an antiquity 

 supported by every feature in its fauna and flora, no less than by 

 its geological structure, and its extinct forms of life^ — affords 

 ample time for the changes in the general distribution of plants, 

 and for those due to isolation and modification under the influ- 

 ence of changed conditions, which are manifested by the 

 extreme peculiarity of many of these interesting endemic forms. 



^ Dr. Hector notes the occurrence of the genus Dammara in Triassic 

 deposits, while in the Jurassic period New Zealand produced the genera 

 Paloeozamia, Oleandrium, Aletliopteris, Camptopteris, Cycadites, Echino- 

 strohus, &c., all Indian forms of the same age. Neocomian beds contain 

 a true dicotyledonous leaf with Dammara and Araucaria. The Cretaceous 

 deposits have produced a rich flora of dicotyledonous plants, many of 

 which are of the same genera as the existing flora ; while the Miocene and 

 other Tertiary deposits produce plants apparently almost identical with 

 those now inhabiting the country. {Trans. New Zealand Inst. Vol. XI. 

 1879, p. 536.) These facts agree well with the origin of the New Zealand 

 flora developed in the last chapter. 



