j2 DICTIONARY OF BIRDS 
Nieremberg, extended his figure of speech, and, while justly deprecating 
the notion that the series of forms belonging to any particular group of 
creatures—the Mammalia was that whence he took his instance—-could be 
placed in a straight line, imagined the various genera to be arrayed in a 
series of contiguous circles around Man as a centre. Though there is 
nothing to shew that Fischer intended, by what is here said, to do any- 
thing else than illustrate more fully the marvellous interconnexion of 
different animals, or that he attached any realistic meaning to his 
metaphor, his words were eagerly caught up by the prophet of the new 
faith. This was William Sharpe Macleay, a man of education and real 
genius, who in 1819 and 1821 brought out a work under the title of 
Hor Entomologice, which was soon after hailed by Vigors as containing 
a new revelation, and applied by him to Ornithology in some “ Observa- 
tions on the Natural Affinities that connect the Orders and Families of 
Birds,” read before the Linnean Society of London in 1823, and after- 
wards published in its 7ransactions (xiv. pp. 395-517). In the following 
year Vigors returned to the subject in some papers published in the 
recently established Zoological Journal, and found an energetic condisciple 
and coadjutor in Swainson, who, for more than a dozen years—to the 
end, in fact, of his career as an ornithological writer—was instant in 
season and out of season in pressing on all his readers the views he had, 
through Vigors, adopted from Macleay, though not without some modi- 
fication of detail if not of principle. What these views were it would be 
manifestly improper for a sceptic to state except in the terms of a 
believer. Their enunciation must, therefore, be given in Swainson’s own 
words, though it must be admitted that space cannot be found here for 
the diagrams, which it was alleged were necessary for the right under- 
standing of the theory. This theory, as originally propounded by 
Macleay, was said by Swainson in 1835 (Geogr. and Classific. of Animals, 
p- 202) to have consisted of the following propositions :1— 
“1, That the series of natural animals is continuous, forming, as it were, a circle ; 
so that, upon commencing at any one given point, and thence tracing all the 
modifications of structure, we shall be imperceptibly led, after passing through 
numerous forms, again to the point from which we started. 
“2. That no groups are natural which do not exhibit, or shew an evident tend- 
ency to exhibit, such a circular series. 
“3, That the primary divisions of every large group are ten, five of which are 
composed of comparatively large circles, and five of smaller: these latter being 
termed osculant, and being intermediate between the former, which they serve to 
connect. 
“4, That there is a tendency in such groups as are placed at the opposite points 
of a circle of affinity ‘to meet each other.’ 
“5, That one of the five larger groups into which every natural circle is divided 
“bears a resemblance to all the rest, or, more strictly speaking, consists of types 
which represent those of each of the four other groups, together with a type peculiar 
to itself.’ ” 
As subsequently modified by Swainson (tom. ctt. pp. 224, 225), the 
foregoing propositions take the following form ;— 
1 I prefer, giving them here in Swainson’s version, because he seems to have set 
them forth more clearly and concisely than Macleay ever did, and, moreover, Swain- 
son’s application of them to Ornithology—a branch of science that lay outside of 
Macleay’s proper studies—appears to be more suitable to the present occasion, 
