Parnassia and its bearing on the Affinities of the Genus. 507 
As we have shown in Section II (iii) of the present paper, not only the 
form but also the anatomy of the staminodes of Parnassia is favourable to 
the comparison with Hyperictan . 
So far, we have been dealing with evidence supporting the view that 
the staminodes of Parnassia represent phalanges of sterile stamens. This 
theory has been disputed, however, by several writers, and we must now 
consider the chief criticisms which have been levelled against it. 
Wettstein 1 took the view that if each nectary of Parnassia corresponded 
to a fascicle of stamens, the number of stalked glands in each nectary would 
be closely similar throughout the genus. However, as he pointed out, the 
number of glands varies widely from species to species. He regarded this 
fact as destructive of the analogy with Hypericum , but it appears to me that 
this variation within the genus does not really render it impossible to 
homologize the nectaries with fascicles of stamens. Among the St. John’s 
Worts the number of stamens in a phalange varies in different species from 
as few as three up to a number too large to be easily counted. In Hypericum 
Elodes we find great variation even within a single flower. This species is 
usually described as having fifteen stamens connate into three bundles. 
I have found, however, that in six flowers taken as random, which had been 
collected in three different localities in two different years, the number of 
stamens in the three phalanges were respectively — 5, 4, 3 ; 5, 4, 3; 6, 4, 3 ; 
5> 4> 3 j 5> 5> 3 5 5> 4 > 3* 
In considering the variability of the nectaries within the genus Parnassia , 
it must also be remembered that these structures are essentially ‘ rudimentary 
organs ’, although now modified for the purpose of insect attraction, and, as 
Darwin 2 pointed out in discussing the subject of rudimentary organs: ‘ In 
closely allied species, also, the extent to which the same organ has been 
reduced occasionally differs much.’ 
I have attempted to show that, from the standpoint of comparative 
morphology, Wettstein’s objection to the view that the nectary of Parnassia 
is equivalent to a phalange of stamens is not a conclusive one. There is 
also another objection to be met, namely that brought forward by the same 
author on teratological grounds. 3 He described two flowers of Paimassia 
palustris which were abnormal as regards the androecium. In one of these 
the stamens bore outgrowths resembling the glandular processes of the 
staminodes, and in the other the fertile stamens were normal, but the 
staminodes showed transitions between their usual form and the form of 
a normal fertile stamen. From these observations, Wettstein drew the con- 
clusion that the staminode is the equivalent of a single stamen, not of 
1 Wettstein, R. von : Zur Morphologie der Staminodien von Parnassia palustris. Ber. d. 
deutsch. bot. Gesellsch., Bd. viii, 1890, p. 308. 
2 Darwin, C. : The Origin of Species, sixth ed., London, 1894, p. 374. 
3 Wettstein, R. von: 1 . c., p. 305. 
