Proceedings of the Linnean Society of London - University Library

LINNEAN SOCIETY OF LONDON 2$
that the Linneau morphology was based upon that of Jung, which,
by the time Linnaeus wrote his ' Funclameuta Botauica' (1736),
had become common knowledge. That work shews a considerable
advance towards a more detailed and comprehensive terminology :
but the goal was not reached until the publication, in 1751, of the
' Philosophia Botanica,' which gave to Botany an unrivalled
descriptive apparatus, and must always be regarded as one of the
greatest of the many great achievements of Linnaeus.
As for the theoretical aspect of morphology, the dissertation
on ' Metamorphosis ' (Amoen. Acad, iv.) and the two on ' Prolepsis
' (Amcen. Acad, vi.) are the recognized contributions
of Linnaeus to this subject. The term ' metamorphosis ' has
certainly a morphological sound, but it must be borne in mind
that it did not mean the same thing when used by Linnaeus
as it did when used by Goethe. In its modern sense it
refers to the adaptation of one and the same member to different
functions ; it is the expression of the physiological division of
labour. Leaves, for instance, may be foliage-leaves, or floral leaves,
or pitchered leaves, or tendrils : all essentially the same, yet all
functionally diverse. But with Linnaeus the word had a much
wider application. It referred, in the first place, to the flowering
of plants, a process that seemed to him to correspond to the
' metamorphosis ' of a chrysalis into a butterfly ; and, secondly,
to the occurrence of varieties and monstrous forms. Nevertheless
he rightly includes, in the second category, such admitted cases of
metamorphosis as the doubling of flowers, and the occurrence of
two different forms of foliage-leaves on partly submerged plants.
The idea of ' prolepsis ' was introduced as an explanation of the
phenomenon of flowering. It is briefly this— that each series of
organs in a flower, the bracts, the sepals, the petals, the stamens,
the carpels, represents the product of a year's development, so
that in the expanded flower there is, as it were, an anticipation of
five years' growth. The idea is fanciful and not well-founded:
yet the dissertations in which it was expounded contain many
interesting and acute observations which clearly sliow that Linnaeus
recognised the morphological identity of floral and other leaves.
But in all this thei'e is no definite advance : there is no more than
a restatement in novel form of accepted view s. A more effective
and more convincing method of attacking morphological problems
was at this very time being pursued by Caspar Friedrich AVolff, who
in advocating epigenesis as against the prevalent theory of
evolutionary development, was investigating the actual facts of
development in both animals and plants : and it is to him, more
than to Limueus, that the progress of morphology at this period
was due.
There is yet one other controversial point to be raised, and that
is tlie suggestion that some germ of the theory of organic evolution
is to be found in the writings of Linnaeus. Such study as I have
been able to devote to these writings has failed to discover anything
of the kind. On the contrary, it has become more and more
clear to me that the idea of the constancy of species is a necessary