492 GEOGRAPHICAL DISTRIBUTION [CHAP. VI 



Letter 375 lepidoptera and other flying insects, many Coniferse, Amen- 

 taceae, Gramineae, Cyperacese, and other wind-fertilised trees 

 and plants, etc. Orchids and Leguminosse are scarce in 

 islets, because the necessary fertilising insects have not 

 migrated with the plants. Perhaps you have published this. 



Letter 376 To J. D. Hooker. 



Down, Jan. gth [1867]. 



I like the first part of your paper in the Card. Chronicle * 

 to an extraordinary degree : you never, in my opinion, wrote 

 anything better. You ask for all, even minute criticisms. 

 In the first column you speak of no alpine plants and no 

 replacement by zones, which will strike every one with 

 astonishment who has read Humboldt and Webb on Zones 

 on TenerifTe. Do you not mean boreal or arctic plants ? 2 

 In the third column you speak as if savages 3 had generally 

 viewed the endemic plants of the Atlantic islands. Now, as 

 you well know, the Canaries alone of all the archipelagoes 

 were inhabited. In the third column have you really materials 

 to speak of confirming the proportion of winged and wingless 

 insects on islands ? 



Your comparison of plants 4 of Madeira with islets of Great 

 Britain is admirable. 



1 must just allude to one of your last notes with very 

 curious case of proportion of annuals in New Zealand. 5 



Are annuals adapted for short seasons, as in arctic regions, 

 or tropical countries with dry season, or for periodically 



1 The lecture on Insular Floras (Card. Chron., Jan., 1867). 

 - The passage which seems to be referred to does mention the absence 

 of boreal plants. 



3 " Such plants on oceanic islands are, like the savages which in some 

 islands have been so long the sole witnesses of their existence, the last 

 representatives of their several races." 



4 " What should we say, for instance, if a plant so totally unlike any- 

 thing British as the *?0nista cdulis . . . were found on one rocky islet 

 of the Scillies, or another umbelliferous plant, Melanoselinum ... on 

 one mountain in Wales ; or if the Isle of Wight and Scilly Islands had 

 varieties, species, and genera too, differing from anything in Britain, and 

 found nowhere else in the world ! " 



5 On this subject see Hildebrand's interesting paper " Die Lebensdauer 

 der Pflanzen " (Engler's Botajiische Jahrbiicher, Vol. II., 1882, p. 51). He 

 shows that annuals are rare in very dry desert-lands, in northern and 



