Proceedings of the Linnean Society of London - University Library

L1NNEA.N SOCIETY OF LONDON. 23
indeed, the interesting dissertation on the buds of trees (Amoen.
Acad. ii. p. 163) be regarded as such.
It will not be irrelevant briefly to consider, at this point, the
interesting question as to the extent to which Linnaeus made use
of the microscope. In his early days he seems not to have used it
at all, for in the introduction to the ' Systema Naturce ' (1735) he
says, almost boastfully, that he had examined nearly all the flowers
of plants with the naked eye only, and without any microscope.
Somewhat later, during his stay iu Leyden (1737-8), he had special
opportunities for microscopical work, since one of his friends there
was " Lieberkiihn, a Prussian, having in his possession incomparable
microscopes," who gave microscopical demonstrations. Linnaeus
relates that, on one such occasion, he was shown the spermatozoa
' of a dog (' Generatio ambigena,' Amoen. Acad. vi. p. 4 ; Sponsalia
Plantarum,' Amoen. Acad. i. p. 79), wheu he drew conclusions as
to their nature antagonistic to those of Leeuwenhoek, the original
discoverer. But he did not apparently pursue his microscopical
studies with any ardour. Among the dissertations forming the
' Anioenitates Academicas ' there are several dealing with topics
that might be supposed to involve the use of the microscope, such
as that on the ' Seraina Muscorum ' (Amoen. Acad. ii. p. 261);
but in only one is there a definite statement to that effect. In the
dissertation ' Mundus Invisibilis,' in which an account of the course
of microscopical discovery is given (Amoen. Acad. vii. p. 399), the
author describes his observations on the Smut of Wheat ( Ustilarjo)
made with a Cuffiuian microscope under the direction of Linnaeus.
This is all the information on the subject that I have been able to
discover.
Nor can it be urged that Linnaeus has strong claims to distinction
as a Physiologist. Though he had as contemporaries such
men as Hales, Duhamel, and Bonnet, and was in constant communication
with Haller, who was distinguished alike as physiologist
and systematist, Linnaeus has not, so far as I have been able to
ascertain, left on record a single physiological experiment. Nevertheless
he proved himself to be an acute observer of physiological
phenomena in nature. Thus in the dissertation ' Somnus
Plantarum ' (Amoen. Acad, iv.) he describes the daily movements
of leaves ; in the ' Philosophia Botanica ' he registers the hours of
opening and closing—the Vigils, as he calls them— of flowers,
fancifully arranging them so as to constitute a " floral clock." The
dissertation ' Calendarium Florae ' (Amoen. Acad, iv.) contains a
number of phaenological observations as to the dates of leafing,
flowering, fruiting, and leaf-fall of plants growing in the Botanic
Garden at Upsala. Further, in the ' Philosophia ' there is a mass
of facts illustrating such important biological features as the
distribution of plants in relation to climate and soil, and the various
modes of dispersal of seeds, Avhich may be regarded as the
foundation of that method of study which, under the name
" QEcology," has developed of late into so considerable a super-
structure.