Robert Brown, a copy of C.K. Sprengel's wonderful book, 'Das
entdeckte Geheimniss der Natur.' For some years before 1862 I
had specially attended to the fertilisation of our British
orchids; and it seemed to me the best plan to prepare as complete
a treatise on this group of plants as well as I could, rather
than to utilise the great mass of matter which I had slowly
collected with respect to other plants.

My resolve proved a wise one; for since the appearance of my
book, a surprising number of papers and separate works on the
fertilisation of all kinds of flowers have appeared: and these
are far better done than I could possibly have effected. The
merits of poor old Sprengel, so long overlooked, are now fully
recognised many years after his death.

During the same year I published in the 'Journal of the Linnean
Society' a paper "On the Two Forms, or Dimorphic Condition of
Primula," and during the next five years, five other papers on
dimorphic and trimorphic plants. I do not think anything in my
scientific life has given me so much satisfaction as making out
the meaning of the structure of these plants. I had noticed in
1838 or 1839 the dimorphism of Linum flavum, and had at first
thought that it was merely a case of unmeaning variability. But
on examining the common species of Primula I found that the two
forms were much too regular and constant to be thus viewed. I
therefore became almost convinced that the common cowslip and
primrose were on the high road to become dioecious;--that the
short pistil in the one form, and the short stamens in the other
form were tending towards abortion. The plants were therefore
subjected under this point of view to trial; but as soon as the