Cockayne. — Botanical Excursion to Southern Islands. 249 



in size and colour, juvenile leaves being nearly twice as broarl 

 and 1'5 times as long as adult leaves ; while, as to colour, 

 the juvenile leaves are reddish-brown and the adult are green. 

 Panax simplex is a plant which exhibits a still more 

 remarkable hetei'ophylly, which, as I stated some years ago 

 (21, p. 355), is not yet understood. Since that time I have 

 been collecting material, and hope to publish my results 

 shortly. As, however, I collected some special evidence on 

 this matter on Auckland Island it may be briefly discussed 

 here. According to Kirk Panax simplex has two quite dis- 

 tinct primary juvenile forms through one or other of which it 

 must pass before it assumes its second later juvenile form and 

 its final adult form. One of the primary juvenile forms has 

 simple leaves and the other has compound leaves, these being, 

 according to Kirk (66, p. 217), "five-foliate on slender pe- 

 duncles ; leaflets petiolulate, linear lobed or pinnatipartite." 

 In his " Forest Flora " Kirk gives figures of the various forms 

 (65, pi. cvi., cvii.). Now, the point which chiefly concerns us 

 here is that Hooker stated that only the entire-leaved seedling 

 form was found on Auckland Island, while Kirk affirms, " It 

 [the entire-leaved form] is the prevalent form on Stewart 

 Island, but the lobulate form occurs there also" (65, p. 211). 

 Taking for granted that the fact of the occurrence of these 

 forms as here stated was correct, I wrote some time ago 

 (22, 355), " Different environment, as will be shown later on, 

 has a most marked effect on the same forms in many plants ; 

 hence this case, granted that the facts are as stated, may be 

 merely a case of different development under different condi- 

 tions." In the accompanying plate may be seen figures of 

 various forms, which certainly throw a new light on our 

 knowledge of this important biological matter. Fig. 1, PI. XL, 

 shows that the form witii deeply cut leaves also occurs in 

 Auckland Island, the seedling in question being collected by 

 me in the forest at Norman's Inlet. Fig. 3 shows a 5-foliate 

 and rather deeply cut leaf, which occurs, moreover, on the 

 same shoot with a ternate leaf (fig. 4). Turning to plants 

 collected by me at Port Pegasus, Stewart Island, in the 

 " rata-pine forest," fig. 5 shows the simple-leaved form and 

 tig. 6 the cnt-leaved compound-leaf form on the same plant. 

 This latter, at any rate, shows that the entire-leaved seedling 

 and the compound deeply cut- leaved seedling are not distinct 

 from one another. The subject has now reached the stage 

 when experimental treatment is demanded. Probably moist 

 air has something to do with the stimulating an hereditary 

 tendency to produce compound trifoliate deeply cut leaves ; 

 but, as I said above, I hope to have some definite statements 

 to make shortly on this matter. The adult form of P. simplex 

 has simplex, oblong-lanceolate, coriaceous leaves, the laminae 



