MIMICRY IN PLANTS. 
3 
a scientific manner, but has collected together a large number 
of curious and interesting facts for others to draw their conclu- 
sions from. At the last meeting of the British Association at 
Edinburgh, Professor Thistleton-Dyer read a short paper with 
this title, but it is very far from exhausting the subject. The 
visitors to the soirees of the Linnean Society for the last two 
years have also been attracted by the collections exhibited by 
that munificent patron of horticulture, Mr. W. Wilson Saunders, 
of so-called “ mimetic plants,” consisting of pairs of species 
resembling one another in their foliage or habit to so extra- 
ordinary a degree — and yet belonging to entirely different 
natural orders — that even a good botanist might well be ex- 
cused for passing them over as identical.* 
Before alluding to the theories which have been broached on 
the subject, let us examine the facts which may be collected, 
and attempt to classify them. The resemblances among plants 
sufficiently close to deserve the appellation of mimicry may be 
classed under two heads : — those which relate to the whole 
habit and mode of growth, and those which refer to the de- 
velopment of some particular organ or part. 
Taking first the former of these classes : there are a number 
of facts which are familiar to every student of botany, and even 
to casual observers. Every one knows that to a certain extent 
that assemblage of characters which we call the habit of a 
plant becomes changed by the circumstances in which it grows. 
A tree in a warm genial climate becomes a dwarf shrub when 
exposed to the bitter cutting winds of northern latitudes ; an 
annual in a temperate changeable climate becomes a perennial 
when transplanted to a tropical country where there is no 
alternation of summer and winter. Hence the general features 
which characterise what have been termed the phyto-geogra- 
phical regions of the earth ; the absence of trees, and the 
prostrate shrubs with a peculiar tortuous and compact habit of 
growth of the Arctic zone ; the green pastures, showy flowering 
annual herbs, and deciduous forests of temperate latitudes ; 
the shiny-leaved evergreen forests and profusion of splendid 
climbers of the tropics ; and the scanty thorny or succulent 
vegetation of the deserts. Under peculiar conditions all plants, 
no matter to what class they belong, or how remote their 
relationship, have a tendency to assume a certain resemblance 
in external features. Plants growing in running water, whether 
flowering or flowerless, Ranunculus or Myriophyllum , Ghara 
or Potamogeton , have the submerged leaves long and filiform, 
* To the courtesy of Mr. Saunders and of his very intelligent gardener 
Mr. Green, who has paid special attention to this subject, we are indebted 
for the facility for making several of the drawings with which this paper 
is illustrated. 
