INSULAR FLORAS. 395 



utterly improbable that I wrote to Dr. Wallace on the sub- 

 ject, and he replied to the effect that it must be a mistake 

 on the part of Dr. Ihering. Returning to the composition 

 of the flora, the chief novelties, assuming that they do not 

 exist on the mainland, which is by no means certain, are : 

 Oxalis Noronluz, Combretum rupicolum, Erythrina auran- 

 tiaca, Cereus insularis, Bwnelia fragrans, Solatium botry- 

 ophorum, Pisonia Darwinii, and Ficus Noronhce. Of 

 course, there is absolutely nothing in the composition of the 

 vegetation to suggest an African origin, and Dr. Ihering 

 may have intended Tristan d' Acunha when writing Fer- 

 nando Noronha. The exceedingly meagre vegetation of 

 South Trinidad (20° $0 S. lat, 29° 22' W.) includes 

 Asplenium compression, a fern only known elsewhere from 

 St. Helena ; and the genus Achyrocline (Compositse), which 

 is both African and American, is represented by an endemic 

 species. It may be mentioned incidentally that Dr. Ihering 

 enters somewhat fully (42) into the origin of the southern 

 insular floras ; and he also discusses the possible and pro- 

 bable agents of dispersal, arriving at much the same 

 conclusions as the writer, though he does not appear to have 

 known of the existence of the reports on the botany of the 

 Challenger Expedition. Turning to Ascension Island, it 

 was not to be expected that after the investigation of such 

 keen botanists as Hooker, Burchell, and others, any species 

 had escaped detection, yet an American expedition adds 

 three proposed new species (43), namely, Rubus nanus, Asple- 

 nium ascensionis, and Nephrodium viscidum. The author 

 was manifestly unaware of the extent to which plants were 

 introduced into the islands from Kew and other places, 

 during the period that cultivation was attempted, for the 

 purpose of supplying ships with vegetables, and even for 

 more ambitious schemes, such as Cinchona planting. There 

 is hardly a doubt that the Rubus is a descendant of an intro- 

 duced species. This view is confirmed by the statement that 

 ' ' it appears to be a very distinct and pecular species of a genus 

 not otherwise represented in the flora of the islands of the 

 South Atlantic ". There is a fragment of the Asplenium in 

 the Kew Herbarium, collected by Don on his journey to 



