the natural Distribution of Insects and Fungi. 51 
The theoretical difference between affinity and analogy may 
be thus explained*: Suppose the existence of two parallel series 
of animals, the corresponding points of which agree in some one 
or two remarkable particulars of structure. Suppose also, that 
the general conformation of the animals in each series passes so 
gradually from one species to the other, as to render any inter- 
ruption of this transition almost imperceptible. We shall thus 
have two very different relations, which must have required an 
infinite degree of design before they could have been made 
exactly to harmonize with each other. When, therefore, two 
such parallel series can be shown in nature to have each their 
general change of form gradual, or, in other words, their rela- 
tions of affinity uninterrupted by any thing known ; when more- 
over the corresponding points in these two series agree in some 
one or two remarkable circumstances, there is every probabi- 
lity of our arrangement being correct. It is quite inconceivable 
that the utmost human ingenuity could make these two kinds of 
relation to tally with each other, had they not been so designed 
at the creation. A relation of analogy consists in a correspon- 
dence between certain parts of the organization of two animals 
which differ in their general structure. In short, the test of such 
a relation is barely an evident similarity in some remarkable 
points of formation, which at first sight give a character to the 
animals and distinguish them from others connected with them by 
affinity ; whereas, the test of a relation of affinity is its forming part 
of a transition continued from one structure to another by nearly 
equal intervals. As a relation of analogy must always depend 
first saw Agardh’s paper and the work of M. Fries on Fungi. If M. Fries borrowed 
from his master Agardh the idea of distinguishing affinity and analogy, which is not 
improbable, we must at least allow him the merit of having greatly improved this part 
of the theory. 
* See Hora Entomologice, p. 362 et seq. 
H 2 on 
