THE NUMBER OF STAMENS AND CARPELS. 233 
CALTHA PALUSTRIS, Linn. 
Hoffmann * has pointed out that with the advancing season 
the flowers of Papaver Rhæas, L., on any given plant become 
smaller, the latest flowers being the smallest of all. Such is 
noticeably the case in Caltha palustris also: the terminal flower 
of a branch is always the largest ; and, further than this, Table X. 
(p. 284) shows that it contains more stamens and carpels than the 
other flowers of the same stem. This Table is derived from the 
study of 102 flowers from the clay cliffs of Cayton Bay, near 
Scarborough. Init the first two figures of each line express the 
sums of the stamens and carpels (or their average) for the 
whole of the flowers of that rank. The terminal flower of a 
branch carrying five flowers is richer in stamens and carpels than 
the terminal flower where fewer flowers are present. And 
therefore the average obtained for the terminal flowers will 
depend largely upon how many weak and how many strong 
branches have been examined. To avoid error from this source, 
in Table X. the statistics of the total of stamens and carpels for 
the flowers of any rank are arranged according to the number 
of flowers borne by the inflorescence. Thus out of the 36 
branches examined, three carried only a single terminal flower; 
and for these three flowers the number of stamens averaged 80°67, 
or considerably below the average of the terminal flowers where 
the inflorescence bore four or five flowers. And for this reason 
Table X. is so arranged that by glancing up the column one can 
see how the average number of stamens increases in flowers pro- 
duced earlier on the same stems. It shows, then, that the oldest 
flowers carry the most stamens and carpels, and that the strongest 
branches, i. e. those which produce most flowers, have in these 
flowers more stamens and carpels than the flowers in corresponding 
positions on weaker stems. 
RANUNCULUS ARVENSIS, Linn. 
A number of plants gathered at Sawbridgeworth (Essex), and 
examined on May 31st, gave results showing that, as in Caltha, 
the first flower carries more stamens than the later flowers ; 
the number of carpels varied irregularly. Owing to the very 
* «Rückblick auf meine Variations-Versuche, /oc. cit. p. 366. 
