634 
Extracts from British and Foreign Journals. 
THE TWENTY-EIGHTH MEETING OE THE BRITISH ASSO- 
CIATION EOR THE ADVANCEMENT OE SCIENCE, HELD AT 
LEEDS, September 22, 1858. 
There are but few of our readers who will not have 
perused with much interest, the proceedings of the above asso- 
ciation, as reported in the public prints. Yet have we thought 
that if some of the subjects brought forward were placed 
in an isolated form, they would prove more impressive and 
profitable to the mind. We have, therefore, selected the 
following from Professor Owen’s admirable opening ad- 
dress : 
Progress oe Zoology, and the Development op Animals. 
Not only has the structure of the animal been investigated, even to the 
minute characteristics of each tissue, but the mode of formation of such con- 
stituents of organs, and of the organs themselves, has been pursued from 
the germ, bud, or egg, onward to maturity and decay. To the observation 
of outward characters is now added that of inward organization and develop- 
mental change, and Zootomy, Histology and Embryology, combine their re - 
suits in forming an adequate and lasting basis for the higher axioms and 
generalizations of Zoology properly so called. Three principles of the com- 
mon ground of which we may ultimately obtain a clearer insight, are now 
recognised 10 have governed the construction of animals : — unity of plan, 
vegetative repetition, and fitness for purpose. The independent series of 
researches by which students of the articulate animals have seen, in the 
organs performing the functions of jaws and limbs of varied powers, the same 
or homotypal elements of a series of like segments constituting the entire 
body, and by which students of the vertebrate animals have been led to the 
conclusion, that the maxillary, mandibular, hyoid, scapular, costal and pelvic 
arches, and their appendages sometimes forming limbs of varied powers, are 
also modified elements of a series of essentially similar vetebral segments, — 
mutually corroborate their respective conclusions. It is not probable that 
a principle which is true for Articulata should be false for Vertelrata ; the 
less probable since the determination of homologous parts becomes the more 
possible and sure in the ratio of the perfection of the organization. 
The study of homologous parts in a single system of organs — the bones — 
has mainly led to the recognition of the plan or archetype of the highest 
primary group of animals, the Vertebrata. The next step of importance 
will be to determine the homologous parts of the nervous system, of the 
muscular system, of the respiratory and vascular systems, and of the diges- 
tive, secretory and generative organs in the same primary group or pro- 
vince. I think it of more importance to settle the homologies of the parts 
of a group of animals constructed on the same general plan, than to specu- 
late on such relations of parts of animals constructed on demonstratively 
distinct plans of organization. What has been effected and recommended, 
