MIMICRY IN PLANTS. 
5 
Euphorbiacese. Additional instances of close general resem- 
blance in habits of plants destitute of the slightest structural 
affinity are afforded by Haworthia , a genus of Liliaceous, and 
Echeveria , a genus of Crassulaceous plants, the former allied to 
the lilies and aloes, the latter to the stone-crops ; and by Figs. 
2 and 3 in our illustration, representing a Cactaceous ( Rhipsalis 
funalis ) and a Euphorbiaceous plant ( Euphorbia TirucaUi ), 
the one from tropical America, the other from South Africa. 
Multitudes of others might have been adduced equally striking. 
If we now pass from general to special resemblances, we find 
ourselves entering on a still more extensive field. Granting 
the Darwinian or Lamarckian theory of the descent of allied 
forms from a common ancestor, and their gradual differentiation 
from one another, a wider margin of separation, as far as mere 
external and less important characters are concerned, appears 
to be allowed to near relatives in the case of plants than of 
animals. The same genus of plants includes frequently species 
much more widely divergent in habit and in all superficial 
features than ever occurs among animals. Hence far more 
play is given to a species to simulate the appearance of another 
species of seme very remote genus, as is often indicated in the 
specific names of plants : Polygonum Convolvulus , Solanum 
jcisminioides , Osmanthus ilicifolius , &c. To such a height in 
even minute details is this resemblance often carried, that the 
most experienced botanist has sometimes referred a plant, on a 
too cursory examination, to a genus or even natural order with 
which it has no affinity whatever. Thus Sir William Hooker 
is said to have actually figured a Veronica as a Conifer ; Kunze, 
a great authority on ferns, considered the curious & 'tangeria 
paradoxa , a Cycad, allied to the Conifers, as a true fern ; and 
Dr. Berthold Seemann speaks of having, in the Sandwich 
Islands, met with a variety of Solanum Nelsoni , 44 which looked 
for all the world like Thomasia solanacea of New Holland, a 
well-known Buettnereaceous plant of our gardens, the resem- 
blance between these two widely-separated plants being quite 
as striking as that pointed out in Bates’s 4 Naturalist on the 
Amazons ’ between a certain moth and a humming-bird.” * 
Less striking instances than this are familiar to all who have 
made plants their study. The pseudo-papilionaceous flowers of 
the Cape species of Polygala have deceived many a young 
botanist. The flowers of Mesembryanihemum remind one 
irresistibly of the compound capitula of Composites. The re- 
markably fern-like foliage, extending even to the dichotomously- 
forked venation, of the hardy Conifer Salisburia adiantif olia, 
is well known to all arboriculturists. The so-called Fungus 
melitensis of Malta is in reality a flowering plant belonging to 
* u Gardener’s Chronicle/’ June 27, 1868. 
