5 6 4 POPULAR SCIENCE MONTHLY. 



kind of raw material, the recognition that a mixture or blending is often 

 more serviceable than when the substances employed are uncombined, 

 the discovery of new processes of treating the articles used in manufac- 

 tures, the invention of improved machinery, all lead to the expansion 

 of trade to the occupation of the people, and to the development of 

 great industrial centers. In science, also, the invention and employ- 

 ment of new and more precise instruments and appliances enable us to 

 appreciate more clearly the signification of facts and phenomena which 

 were previously obscure, and to penetrate more deeply into the mysteries 

 of nature. They mark fresh departures in the history of science, and 

 provide a firm base of support from which a continuous advance may 

 be made and fresh conceptions of nature can be evolved. 



It is not my intention, even had I possessed the requisite knowledge, 

 to undertake so arduous a task as to review the progress which has re- 

 cently been made in the great body of sciences which lie within the 

 domain of the British Association. As my occupation in life has re- 

 quired me to give attention to the science which deals with the struc- 

 ture and organization of the bodies of man and animals — a science 

 which either includes within its scope or has intimate and widespread 

 relations to comparative anatomy, embryology, morphology, zoology, 

 physiology and anthropology — I shall limit myself to the attempt to 

 bring before you some of the more important observations and conclu- 

 sions which have a bearing on the present position of the subject. As 

 this is the closing year of the century it will not, I think, be out of place 

 to refer to the changes which a hundred years have brought about in 

 our fundamental conceptions of the structure of animals. In science, 

 as in business, it is well from time to time to take stock of what we have 

 been doing, so that we may realize where we stand and ascertain the 

 balance to our credit in the scientific ledger. 



So far back as the time of the ancient Greeks it was known that the 

 human body and those of the more highly organized animals were not 

 homogeneous, but were built up of parts, the partes dissimilares 

 {ra avojxoia fxkprj) of Aristotle, which differed from each other in form, 

 color, texture, consistency and properties. These parts were familiarly 

 known as the bones, muscles, sinews, blood-vessels, glands, brain, nerves 

 and so on. As the centuries rolled on, and as observers and observa- 

 tions multiplied, a more and more precise knowledge of these parts 

 throughout the animal kingdom was obtained, and various attempts 

 were made to classify animals in accordance with their forms and struc- 

 ture. During the concluding years of the last century and the earlier 

 part of the present, the Hunters, William and John, in our country, the 

 Meckels in Germany, Cuvier and St. Hilaire in France, gave an enor- 

 mous impetus to anatomical studies, and contributed largely to our 

 knowledge of the construction of the bodies of animals. But whilst by 



