Man's ideas of the use of flowers--Sprengel's great discovery--Insects, not man, consulted--Pollen carried to set seed--Flowers and insects of the Whinstone Age--Coal Age flowers--Monkey-puzzle times--Chalk flowers--Wind-blown pollen--Extravagant expenditure of pollen in them--Flower of the pine--Exploding flowers--Brilliant alpines--Intense life in flowers--Colour contrasts--Lost bees--Evening flowers--Humming birds and sunbirds--Kangaroo--Floral clocks--Ages of flowers--How to get flowers all the year round--Ingenious contrivances--Yucca and fig--Horrible-smelling flowers--Artistic tastes of birds, insects, and man. For many centuries flowers were considered as pleasing and attractive decorations stuck about the world in the same way as they are put in a drawing-room in order to give people pleasure. Very soon they were found to be extremely useful in poetry, sometimes to point a moral or disguise a sermon, like the primrose in _Peter Bell_, but more generally to produce a good impression on the BELOVED OBJECT. Burns puts the usual view of flowers very nicely in the following: "But I will down yon river rove amang the woods sae green, and a' to pu' a posie to my ain dear May." Possibly this is the meaning also in the exquisite lines of Shakespeare about the pansy:-- "Yet marked I where the bolt of Cupid fell: It fell upon a little western flower,-- Before milk-white, now purple with love's wound,-- And maidens call it, love-in-idleness." Even if there is no particular meaning, the "little western flower" gives point and beauty to the lines. People only began to understand flowers about the year 1793, when Christian Conrad Sprengel, Rector of Spandau, near Berlin, published a very interesting work. He had discovered that the beauty of flowers and their colour and shape were by no means intended solely to please _human_ eyes, but that they were designed to attract and allure the eyes of _insects_. Before his time there had been many guesses. Indeed, Theophrastus (born 371 B.C., and often mentioned in this work) seems to have quite well understood why flowers produce pollen, and that the fruit would not set and form seed unless pollen was carried to the female part of the flower. He mentions that the Pistacio has both male and female plants, and that Palms only form dates when the pollen is carried to the female tree. This experiment with the Date-palm was tried in 1592 by an Italian (Alpino) in an Egyptian tour, and the Englishman, Jacob Bobart, the Pole, Adam Zaluzianski (the latter in the same year) confirmed the general idea. Then in the year 1694 Rudolp Jacob Camerarius, a German, carried on a few more experiments, but no real definite advance was made until 1793, in the very midst of the French Revolution.[25] [25] The historical account by Bonnier, _Cours de Botanique_, is very interesting and complete.