ANIMAL TISSUES. 



The Tissues of Animals. 



Nature, in the structure of animals, has exhibited inconceivable 

 resources of art. Not only is the body as a whole, not only are its 

 grosser parts, but even the smallest parts of the organs are ma- 

 chinery; and the knife of the anatomist exhibits to us, even to the 

 simplest fibre, nothing but parts constructed for a purpose. The 

 whole body consists of many members : the members themselves 

 consist of muscles, vessels, and nerves; the muscles again qf 

 tissues, vessels, fibres, &c. Such a body may well be called 

 organised. 



In order to form an idea of the texture of animals, we must go 

 to work as the chemist does. He divides the parts which compose 

 bodies into proximate and ultimate constituents, and terms those 

 constituents ultimate, or elements (elemental), which by his art he 

 can separate no further into heterogeneous parts. In the same way 

 we find in the textures of animals proximate and ultimate con- 

 stituents. Of the last, or the organic elements (elementa organica], 

 we shall speak hereafter : the first question is what are the proxi- 

 mate constituents? (paries constituentes proximce). They are called 

 Tissues (Tefa). 



BICH AT was the founder v of the science of the organic tissues in 

 man, and named it General Anatomy. In the investigation of the 

 tissues he had recourse to chemical reagents, to maceration and 

 partial decomposition in water. He described each tissue according 

 to its physical and chemical properties, its physiological pheno- 

 mena and its morbid changes. After him this science was ad- 

 vanced by MECKEL, HEUSINGER, and BECLARD 1 in the same spirit. 

 Within the last ten years it has received a totally different direction 

 through microscopic research. By means of it General Anatomy 

 has become, for the most part, Microscopic Anatomy. Our immortal 

 LEEUWENHOECK, about a century and a half ago, had collected 

 much material which remained almost unused; until, in our day, 

 with the improvement of the compound microscope, a more general 

 interest in such enquiries has been excited, and the importance of 

 the knowledge of the minutest organic constituents to accurate 



1 Here it may suffice to refer to the well-written and succinct manual of the last 

 named author : EUmens d' A natomie generate (a me e*dit. Paris, 1827. 8vo.) 



