193 



ANAS. 



ANATOMY. 



191 



common in the northern seas, and in Britain is frequently taken on 

 the east coast of Scotland and the Orkneys, though rare on the 

 English shores. Its range extends to Greenland. It grows to the 

 length of 6 feet, and is a ferocious and formidable animal, destroying 

 the nets of fishermen ; when caught it defends itself to its last gasp, 

 inflicting severe wounds by means of its powerful teeth and jaws. It 

 lives chiefly on Crustacea and testaceous mollusca, and, like most fish 

 which subsist on such food, its flesh is excellent eating, though, from 

 the ugly appearance of the animal, usually rejected. It finds its way 

 however to the Edinburgh market, where, by naturalists especially, 

 whose knowledge of its good qualities enables them to vanquish 

 their prejudices against its aspect, it is much esteemed. The 

 Cat-Fish is of a light gray colour marked with seven or eight broad 

 vertical bands of bluish gray. When old it becomes darker. Its 

 skin is covered with slime. (Yarrell's British Fiihea.) 



ANAS, the Duck, a genus of birds under which Linnaeus included 

 a great number of species now separated into several genera by recent 

 naturalists. [Dut'KS.] 



ANASTATICA, a genus of plants belonging to the natural order 

 fcrtfe. One species, A. hierochuntina, is the Hose of Jericho. 

 [JERICHO, ROSE OF.] 



ANASTO'MOSIS, from ovi, through, and <TT<W, a mouth, signifies 

 the communication of blood-vessels with each other by the opening of 

 the one with the other. The blood-vessels are the tubes by which 

 the different parts of the body are supplied with nourishment. If the 

 blood-vessels destined to nourish a part be obstructed, so that it 

 cannot receive a due supply of blood, that part must necessarily die, 

 or, aa it is technically termed, mortify. But the blood-vessels are 

 soft compressible tubes, liable by innumerable circumstances to have 

 their sides brought so closely into contact as to prevent the flow of a 

 single particle of blood through them. In order to prevent the con- 

 sequences that would result to the system from the operation of 

 causes thus tending to impede the circulation, provision is made for 

 the freest possible communication between the main trunks of the 

 bloc id-vessels and their branches, and between one branch and another. 

 All the branches which form such communications are called anatto- 

 moting branches, and this union of branch with branch is termed 

 A nattomotit. 



ANATASE, in Mineralogy, a variety of Titanic Acid. [TITANIUM.] 



ANATHEKUM, a genus of Grasses, belonging to the group of 

 which species yield fragrant volatile oils. A. muricatwn is the Vetian 

 of the French and the Xhiu of the Hindoos. Its fragrant roots are 

 employed in making tatties, covers for palanquins, &c. It is admin- 

 istered medicinally, and has stimulating and diaphoretic qualities. 

 A. nardus is also, on account of the volatile oil it contains, called 

 Ginger-Grass, or Koobel. 



ANATIlXiE (Leach), the Duck kind, a group formed by Dr. Leach 

 to include his genera formed from the great genus Amu of Linnoms. 



[Dvcn.1 



ANA TOMY, from a Greek term (iraroju^), which literally signifies 

 the separation of a thing into parts by cutting ; ' the term Anatomy 

 is used to signify particularly, dissection, or knowledge acquired by 

 dissection. Anatomy is at once an art and a science ; an art, inasmuch 

 as the pursuit of it requires skilful manipulation ; and a science, 

 inasmuch as certain general principles are deducible from it. The 

 object of anatomy is to ascertain the structure of organised bodies. 

 Of the two great kingdoms of nature, the inorganic and the organic, 

 it comprehends the whole range of the latter. Like the organised 

 kingdom itself, it forms two divisions, the one including the structure 

 of plants Vegetable Anatomy ; the other the structure of animals 

 Animal Anatomy. Animal Anatomy is divided into comparative and 

 human : Comparative Anatomy includes an account of the structure 

 c'f all classes of animals, excepting that of man ; Human Anatomy is 

 restricted to an account of the structure of man only. Human 



my is subdivided into descriptive, general, and pathological 

 Dftrrii^in .\ ,>'>', ,:i*i comprehends a description of all the various 

 parts or organs of the human body, together with an account of their 

 situation, connections, and relations, as these circumstances exist in 

 the natural and sound, or, as it is technically termed, the normal, 

 condition of the body. The human stomach, for example, is composed 

 of a number of membranes, which are united in a particular manner ; 

 ii number of blood-vessels which are derived from particular arterial 

 trunkrt ; n number of nerves which proceed from a particular jwrtion 

 of the bruin and spinal cord; a number of absorbent vessels, and so 

 on ; moreover, this organ is always placed in a particular cavity of the 

 licwly, and is always found to have certain specific connections or 

 relations with other organs. The anatomy of the human stomach 

 comprehends an account of all the particulars of this kind, which are 

 uniformly found to concur in all human bodies in which the confor- 

 mation is regular or natural ; and so of every other organ f the 

 body : and because such an exposition of the structure of the various 

 organ* includes a description of all the circumstances that relate to 

 their organisation, it is called Descriptive Anatomy. 



After the study of the human body in this mode has been carried 

 to a certain extent, with a certain degree of success, it necessarily 

 gives origin to a second division of the science, that termed Uencral 



iny. It is found, that many of the circumstances which belong 

 to any one organ, belong at the same time to several organs; and that 



KAT. HI*! 1 . HIV. VOL. I. 



thus several individual circumstances are common to many organs. 

 Of the membranes, for example, of which it has been stated that the 

 stomach is composed, some are common to it and to the intestines, 

 to the bladder, to the heart, to the air-passages, and so on. In 

 like manner with respect to any one of these membranes, when its 

 structure is carefully examined, it is found that in many points its 

 organisation is exactly similar to that of all other membranes. This 

 view extended leads to further important and interesting results. 

 All the arteries of the body, whatever their situation, size, or office, 

 are found to be composed essentially of the same substances, disposed 

 in nearly the same order and form. All the veins have, in like 

 manner, a structure essentially the same. All the absorbent vessels, 

 all vessels of every kind, all the bones, muscles, and nerves, the whole 

 external covering of the body or the skin, widely as these various 

 structures differ from each other, present no material difference as far 

 as regards the organisation of each particular class. Hence various 

 organs of the body are disposed into what are called common systems, 

 and these common systems are said to consist of common substances 

 or tissues. All the vessels, for example, are collected and arranged 

 under one common class, called the vascular system : in like manner, 

 all the bones are collected and arranged under another class, called 

 the osseous system ; all the muscles under another, called the mus- 

 cular system ; all the nerves under another, called the nervous 

 system, and so on. The material that enters into the composition of 

 each of these systems consists of a substance of a peculiar nature ; but 

 as this substance is more or less generally diffused over the whole 

 body, entering as a constituent element into the various organs, it is 

 termed a common substance, or tissue. What is termed the common 

 cellular or areolar tissue, for example, is the substance which enters 

 most commonly into the compositition of the organs of the body ; 

 the muscular tissue is the substance of which the muscles are com- 

 posed ; the nervous tissue is the substance of which the nerves are 

 composed : and thus, the structure of the body, analysed in this 

 mode, innumerable and complex as the substances appear to be of 

 which it consists, is ultimately reduced to a very few simple materials, 

 by the combination and modification of which all the different animal 

 substances are produced. 



General Anatomy also includes the study of certain fluids from 

 which the membranes or textures are formed. The following is a list 

 of the fluids and textures, given by Dr. Sharpey in Quaiu's ' Elements 

 of Anatomy : ' 



The Blood, Chyle, and Lymph. 



Epidermis Tissue (including Epithelium, Cuticle, Nails, and Hairs). 



Pigment. 



Adipose Tissue. 



Cellular Tissue. 



Fibrous Tissue. 



Elastic Tissue. 



Cartilage, and its varieties. 



Bone or Osseous Tissue. 



Muscular Tissue. 



Nervous Tissue. 



Blood-Vessels. 



Serous and Synovial Membranes. 



Mucous Membranes. 



Skin. 



Secreting Glands. 



These textures and fluids will be treated of under their respective 

 heads. 



Descriptive and general anatomy, then, include an account of the 

 structure of the body as it exists in the state of health. But there is 

 no organ of the body, and no tissue which enters into its composition, 

 which is not subject to disease ; in consequence of disease, the regulat- 

 or natural structure of the component substances of the body becomes 

 changed in a great variety of modes. That part of anatomy which 

 displays these diseased or morbid changes, and which describes all 

 the circumstances relating to them, is called Pathological or iforbid 

 Anatomy. We may say, then, that Descriptive Anatomy comprehends 

 an account of all the parts or organs of the body as they exist in the 

 state of health ; General Anatomy comprehends an account of all the 

 separate substances of which those organs are composed, not as these 

 substances exist combined in organs, but as they form distinct and 

 peculiar substances ; Pathological Anatomy comprehends an account 

 of all the changes of structure produced by disease, whether in 

 individual organs, or in the primitive or common substances of which 

 these organs are composed. 



The term A nalomy, as we have seen, is chiefly applied to the science 

 which determines the nature and relations of the various organs of 

 the human body. A general term is here used in a restricted sense. 

 On the other hand, when we would express the extension of the 

 science of anatomy to the whole animal creation, we employ the 

 general term with the addition of the word Comparatire. This 

 iinoinaly has doubtless proceeded from the circumstance that, till 

 within a very recent period, thn study of animal structure was almost 

 exclusively confined to the human subject ; and that even zoologists 

 were contented with inquiring into the functions of animals, instead 

 of determining the character of the organs which were connected 

 with those functions. By the term Cvmparalh'e Anatomy is understood 



