228 MR. I. H. BURKILL ON SOME VARIATIONS IN 
stage in the disappearance, are fewer in number. However, the 
facts to hand are insufficient to admit of any certainty. 
A reduction in the number of stamens present in any individual 
flower does not predispose to contabescence in those remaining ; 
for taking the figures in Table I., we find that in the 5243 flowers 
which contain no staminodes, the percentage of aborted stamens 
is 61:29 (88:71 per cent. stamens developed), while in the 443 
flowers which contain staminodes this same percentage is 61:74. 
(19:92 stamens and 18:44 staminodes developed), z. e. they scarcely 
differ. 
Further, Table I. shows us that just as the 3-stamened flowers 
arethe most numerous, so amongst those with staminodes, flowers, 
where these and the stamens together make up three, are the 
most numerous, z. e. flowers with two stamens and one staminode, 
with one stamen and two staminodes, or with no stamens and 
three staminodes. Next to these in number come those where the 
stamens and staminodes together number four. This suggests 
that the staminodes are stamens of which adverse circumstances 
have caused the abortion (7. e. it is a reduction of the androecium 
beyond the average degree), and are not due to favourable 
cireumstances calling forth an imperfect stamen in a place where 
otherwise nothing would have been developed: in other words, as 
far as Stellaria is concerned, contabescence and complete abortion 
are only forms of the same reaction differing in degree; the 
one is not consequential in any way of the other. Only we 
must remember that the more stamens are aborted, the fewer 
are present to be contabescent, and therefore the number of 
aborted and contabescent stamens cannot increase propor- 
tionally. 
Position of the Stamens which most frequently abort.—In a 
large number of Chickweed flowers the position of the stamens 
was noted, and from the results we can trace two degrees in the 
reduction of the 10-androus flower to its present usual 3-androus 
condition :— 
(i) Abortion of the outer ring of stamens of the obdiploste- 
monous flowers, z. e. those superposed to the petals. 
(ii) Abortion of the two stamens of the inner ring which are 
superposed to the two outermost sepals of the quincuncially 
arranged calyx. 
That these two degrees in the reduction of the stamens are 
