3° CHELTENHAM COLLEGE NATURAL HISTORY SOCIETY, 
We must remember that studying fertilisation means studying 
plant development, and it will be well to have before us a notion of 
what constitutes a primitive flower. Botanists believe that the features 
are (1) a simple, regular corolla and calyx, each consisting of five 
members ; (2) petals and sepals all separate, so that any honey lies 
exposed to all comers ; (3) a large number of achenes or seed vessels ; 
and (4) a great quantity of pollen. We see that the buttercup 
(Ranunculus) and Cinquefoil (Pofentitia) fulfil this definition. As 
flowers develop, there is an economy of pollen, a production of honey 
(more or less concealed), of a tube to keep off certain insects, and 
in some cases of irregularity of form, accompanied by variegation of 
colour. 
We said that an insect visiting flowers is seeking for pollen or 
honey, and asa rule it finds by experience that only flowers which 
advertise theinselves by bright colour or smell keep a store of honey 
at home. Some flowers, it is true, are not above deceit—the herb 
Paris has a shining black pistil, which looks as though it were covered 
with honey, although it is quite dry, and the beautiful grass of Par- 
nassus has four little pouches at the base of its corolla, which present 
the appearance of drops of honey. 
We will now examine one or two orders, noticing as we go the 
bearing of cross-fertilisation on development :—Ranunculacee.—This 
is termed a primitive order, because all the members fulfil some and 
many of them all the conditions of a primitive flower. I think the 
chief interest of the order lies in noticing the different ways in which 
cross-fertilisation has been accomplished by the more advanced mem- 
bers of the order, in spite of the fact that they have retained most of 
their primitive conditions, the result being that, with a large basis of 
resemblance in the essential parts, we have a great variety of form in 
the petals and position of the honey. This 1s quite different from 
what we should find in an advanced order, such as the Composite, 
where the individual members have all in a body departed from the 
original primitive type, the variation produced tending to favour cross- 
fertilisation, (e.g.) an aggregation of flowers in a head, a tubular corolla, 
etc.) Consequently, in order to put on the finishing touches, only very 
slight changes are necessary, and we find a similarity between all the 
mechanisms. Three species of Ranunculus, acrts, repens, and bulbosus 
are known by the name of Buttercups. They are visited by insects in 
equal abundance, and even the hive bee cannot distinguish between 
them. The outer stamens dehisce (or open) before the stigmas are 
ripe, and they open away from the centre of the flower. In this stage 
