346 Transactions. — Botany. 



there the extreme variabiHty to be found in these Veronicas. In drawing up 

 the synopsis, I have found it in many cases extremely difficult to give 

 diagnoses embracing all the forms of the species, and consequently in these 

 cases the description must be looked upon as representing only the most 

 common form of the species. But the species are not all so variable — many 

 of them are very distinct. It is chiefly in sections 2, 4, 5, 6, and 7 of sub- 

 genus II. that these variable forms are to be found. The most difficult 

 forms will be found pointed out in the notes attached to the specific 

 characters which I have made as complete as my materials admitted.* 



The question as to what is the cause of the great variations of these 

 plants is perhaps a difficult one to answer, and offers a very wide field for 

 future investigation. It has been suggested that the numerous so-caUed 

 intermediate forms are the results of natural hybridization, and that many 

 of our so-called " species " are not true species but natural hybrids. But, 

 without going into the vexed question of what constitutes a " species," I feel 

 perfectly satisfied that the hybridism theory is quite untenable. We now 

 know that self-fertile plants are by far the most abundant, and exhibit the 

 greatest amount of endurance and greatest range of temperature ; that, in 

 fact, plants capable of self-fertilization are those most fitted to survive in 

 the struggle for existence, as indeed we may see am^jly illustrated in the 

 naturalization of European plants in this colony, the said introduced plants 

 being nearly all self-fertile. Now when a plant contains within its own 

 flower all the required elements for the reproduction of its kind, it is sm^ely 

 extremely improbable that it will cross with any other plant, no matter how 

 closely allied the latter may be ; and such crosses have been found by all 

 investigators to be exceedingly rare, although, of course, they cannot be 

 said to be impossible. Now I have ascertained, by careful experiments, that 

 the great majority of the New Zealand species of Veronica, including all the 

 variable ones, are perfectly self-fertile, that is, that the pollen of any one 

 flower is active when applied to the stigma of the same flower, and that 

 when the species are left in a state of nature the pollen is so applied by the 

 natural arrangement of the parts. In most cases, indeed, it is scarcely 

 possible for the corolla to shrivel without bringing the anthers in contact 

 with the stigma. Thus although hybridization is perfectly possible, it must 

 be considered as extremely improbable, and certainly it does not account for 

 many of the phenomena shown in the genus. Moreover the varieties do not 

 show the usual characteristics of hybrids except in their being in so many 

 cases exactly intermediate. Hybrids raised in gardens are usually sterile, 

 and when fertile their seedlings show a remarkable amount of variation, as 



* It has only been possible to print the description of the author's new species. — Ed. 



