438 TransactioJit. 



species which range through the whole length of the colony 

 there is a considerable difference between the times at which 

 they flower in the North Island and South Island respectively, 

 the same species blooming quite six weeks later in Canterbury 

 than at the Bay of Islands. It appears to me that this difference 

 in the flowering period supplies us with a simple means of decid- 

 ing in which of the two localities Raoul's specimens were obtained. 

 If they were gathered in December at the Bay of Islands, then 

 the plant will also flower in that month at Kaitaia ; if, on the 

 other hand, we accept Raoul's statement that they were col- 

 lected at Akaroa, it is obvious that the flowering season at 

 Kaitaia will be about six weeks sooner, or about the end of Octo- 

 ber. I therefore applied to Mr. R. H. Matthews for information 

 as to the time of flowering at Kaitaia. He has gone into the 

 matter with considerable care, and informs me that the first 

 fully expanded flowers were noticed on the 19th October. On 

 the 27tli October the plant was in full flower, continuing in that 

 state through the early part of November, but entirely passing 

 out of bloom before the end of the month. I think that it will 

 be admitted that these observations of Mr. Matthews prove — 

 (1) that Raoul could not have collected flowering specimens 

 at the Bay of Islands, for the simple reason that the plant was 

 not in flower at the time of his visits ; and (2) that the flowering 

 period at Akaroa would probably be in the month of December, 

 thus harmonizing with Raoul's own statement. This evidence 

 is, of course, of an indirect nature, but it appears to be quite 

 sufficient to warrant us in accepting as correct Raoul's original 

 habitat as published by him. 



In the present state of our knowledge it is premature to specu.- 

 late as to the reasons why Pittosporum obcordatum should ap- 

 parently be confined to two localities so far apart as Kaitaia and 

 Akaroa. The facts have yet to be collected which will explain 

 such remarkable instances of discontinuous distribution. But 

 it may be observed that systematic inquiry into the causes 

 which have operated in such cases is of greater importance than 

 would appear at first sight. If we could fully explain the dis- 

 continuous distribution of the plants mentioned at the beginning 

 of this paper, we should know much of the past history of the 

 flora and its gradual development, and we should be more fully 

 acquainted with the vicissitudes of climate and the changes 

 which have taken place in the physical conditions of the country. 



One important consideration remains for discussion. Sir 

 Joseph Hooker, in the "Flora NoviB-Zealandise" (vol. 1, p. 22), 

 remarks with respect to Piftosporum obcordatum, " It presents 

 some peculiarities of form and habit shared by several New Zea- 

 land plants of very different genera, which are not easily dis- 



