of certain Birds of Cuba. 9 
universe given to it from the days of Plato and Cicero*, that 
Linnezus, Pallas and Desfontaines, have mentioned certain ana- 
logies in nature as distinct from affinitiest; and that one of the 
most distinguished zoologists of the present age and a foreign 
member of this Society, Professor Gotthelf Fischer of Moscow, 
has stated the progression of certain series of affinity being in cir- 
clest. Ican safely say, however, that as [ arrived at the know- 
ledge 
* The ancient authors on this subject, however, really deserve but little attention ; 
for they all arrived at their conclusions by the @ priori mode of argument,—a mode 
totally inapplicable, nay even injurious, to a science like Natural History, which must 
always depend upon experience and observed facts. 
+ Aristotle in the Historia Animalium, lib. 11. c. 1. says, when speaking of animals 
generally, Ta jev xat’ avaroyiav adiahopa povov, Tw vyever Oe Erepa. Now if this passage 
be taken literally, we must give him full credit for making the distinction between affi- 
nity and analogy. But I confess, that on looking at the context, and above all, at his 
explanation of an arrangement xar’ avadoyiay, as above mentioned, I suspect that his 
idea of analogy did not reach beyond the comparison of organs: as when we say the 
wing of a bird represents the hand of a man; which comparison, however necessary to 
the full understanding of the analogies between different beings, is very far from ex- 
pressing the whole of them. However this may be, it is curious to observe that so 
little attention should have been paid to this observation of the father of natural history, 
that “‘some animals, which agree in analogy, are yet different from each other in afli- 
nity.” 
{ It seems to me to be quite unnecessary to discuss in this place what Plato meant 
by saying, that in nature all things terminate in their contraries,—an expression which 
Linneus borrowed in his Diary, and appears to have attached meaning to as con- 
nected with the number five. Such disquisitions are as little likely to prove satisfac- 
tory, as those arguments drawn from the first chapter of Ezekiel, which led a Northern 
writer, Mr. Macnab, to declare a circle to be the plan of Nature, long before I 
attained the knowledge of the fact by observation. Naturalists have nothing to do 
with mysticism, and but little with @ priori reasoning. I have therefore infinitely less 
hesitation in citing the following passage from Hermann :—“ Neque enim ad affinita- 
tem indicandam per omnem charte latitudinem diducere lineam placuit, sed inter 
nomen et charte: marginem posuimus asteriscum qui flexa in orbem chart& incidit in 
similem alium cujus ope duo in utraque extremitate posita corpora inter se conjun- 
guntur, unde miré implicite et concatinate inque circulum redeuntes affinitates tanto 
VOL. XVI. c magis 
