40 ANATOMY. 



line as the bones, raised up and snipped away. The soft pulpy brain, much 

 smaller, and more pointed in front, than the human brain, and nearly smooth 

 as compared with that (see Figs. 58 and 59), is then to be removed by being 

 raised up in front, certain bloodvessels and all the nerves given off from its 

 under surface being divided one by one, as they pass to their respective open- 

 ings in the base of the skull : last of all, the thick prolongation from the base 

 of the brain, down the spinal canal, called the spinal cord, will require to be 

 cut across. The distinction between the cerebrum and cerebellum having been 

 noticed, and the layer of arachnoid with the subjacent vascular pia mater still 

 covering their surfaces, the course of the spinal cord down the backbone may 

 be either traced by cutting open the vertebral canal (a very difficult task), or 

 a fine twig or wire may be thrust down to demonstrate the existence of a 

 canal. It is from the sides of the spinal cord that the nerves of the walls of 

 the trunk, and the nerves of the limbs are given off. 



The practical information obtained by such an examination of the various 

 organs in the body of a dog or rabbit, as is above prescribed, must now be 

 transferred, as it were, to the study of the human organism. Beside those 

 marked differences in the configuration of certain parts which have been inci- 

 dentally mentioned, and others which will be obvious enough, it must by no 

 means be forgotten that the muscles are paler, and their tissue softer, and 

 that the intermediate areolar tissue, the ligaments, bloodvessels, and nerves, 

 being on a smaller scale, have an apparently finer structure, than in man. 



To guard against any misconceptions, or any confusion between the char- 

 acters of the organs in the animal and in man, it will be well, at this stage, to 

 re-peruse the previously given description and the woodcuts of the organs of 

 the Human Body. 



THE TEXTURES OF THE BODY. 



GENERAL CONSIDERATIONS. 



THE different organs of the body, which we have now examined 

 generally, are no more composed each of a uniform homogeneous ma- 

 terial than is the body itself. On the contrary, every organ is built 

 up of several very distinct elements which are called Textures or Tis- 

 sues. 



Thus, the heart, which speaking in general terms is said to be a 

 hollow muscular organ, is really composed of the following parts. 

 Externally, we find a thin reflected layer of the serous membrane 

 called the pericardium, which itself consists of a basis or web of dense 

 areolar connective tissue, covered with a stratum of epithelial tissue ; 

 next beneath this is the proper substance or striped muscular tissue of 

 the heart, which is mixed with a very minute quantity of fine areolar 

 tissue; deeply seated in the interior of the heart are certain rings, 

 cords and valves or flaps composed of fibrous connective tissue ; and 

 the internal surfaces of its cavities are lined with a thin smooth mem- 

 brane, named the endocardium, which is like a serous membrane in its 

 nature, being composed of a very fine layer of areolar connective tissue 

 covered with a very delicate epithelium. Besides this, the heart has 

 its proper bloodvessels and absorbents, all of which have their compo- 

 nent tissues, viz., areolar, elastic, unstriped muscular, and epithelial 

 tissues. Lastly, there are the nerves and ganglia, which consist of 

 the nervous tissues, supp6rted by sheaths of areolar connective tissue. 

 So on all the organs of the body. 



