1854.] OF THE ROYAL INSTITUTION. 413 
WEEKLY EVENING MEETING, 
Friday, March 24. 
Wiiu1am WILBERForcE Birp, Esq., Vice-President, 
in the Chair. 
Epwin LaNKESTER, M.D., F.R.S. 
On the distinctions supposed to limit the Vegetable and Animal 
Kingdoms. 
In commencing, the Lecturer made some general remarks on classi- 
fication, and pointed out the importance of accurate definitions in 
order to constitute the classes, families, genera, and species of the 
naturalist. The importance of defining species was greater than that 
of larger groups, because these were composed of species. As genera 
were collections of species, and families collections of genera, so the 
animal and vegetable kingdoms were but collections of species. The 
difficulty in distinguishing between the animal and vegetable king- 
doms consisted in our imperfect knowledge of the characters of 
species which existed on what might be called the limits of the two 
kingdoms. The history of the attempts at defining animals and 
plants, for systematic purposes, would afford the best idea of the 
nature of these difficulties. The definition of Linnzus, that minerals 
grow, plants grow and live, animals grow, live, and feel, was first 
examined. In order to apply this definition, the terms growth, life, 
and feeling, required explanation. Growth simply indicated increase. 
The term /ife could not be defined in such a manner as to render it 
inapplicable to the physical phenomena of the inorganic world and 
at the same time embrace the lowest forms of organised beings. 
Feeling could not be defined so as to separate the movements evinced 
by so many members of the vegetable kingdom on the application of 
external stimulants, as the movements of the leaves of the sensitive 
plant, of the Dionea muscipula, the stamens of the barberry, and 
the closing and unfolding of flowers from those of the animal king- 
dom. Such were the distinctions attempted to be made by one who 
disregarded the use of the microscope. 
One of the most obvious distinctions between the organic and in- 
organic kingdoms was the presence of the cell in the former. Under 
some circumstances it was not easy to detect the cell, as in certain 
fossils, and sometimes inorganic matters assumed a cellular form. 
Another distinction adopted by naturalists, even since the general 
introduction of the microscope into natural history inquiries, was, 
that animals moved, whilst plants were fixed. This distinction, 
though applicable to the higher forms of plants and animals, was 
