SYSTEMATIC ANALYSIS OF APPARATUS 



127 



479. THE SPLEEN is a large organ, chiefly composed 

 of cells, and as the Blood circulates among them its con- 

 tents are modified by the cells, and returned again to 

 the Blood. 



FIG. 112. FIG. 113. 



Fig. 112 represents concave surface of Spleen, with which the stomach 

 is in contact ; 6, branches of Arteries ; 7, Vein. 



Fig. 113: 6 represents the Thyroid Gland, like a saddle across the 

 windpipe, 7, just below the Larynx. It is named from the Thyroid Car- 

 tilage, 3. 



480. THE THYROID AND THYMUS GLANDS are simi- 

 larly constructed organs, that, like the others that have 

 no other inlet or outlet except the Blood-tubes, must 

 be modifying organs, though in what peculiar way they 

 modify the Blood is not known. 



481. THE SUPRA-RENAL BODIES are small parts found 

 at the summits of the Kidneys, the use of which has 

 been supposed to be modificatory by some and nervous 

 by others. As they have no outlet nor inlet, except blood- 

 tubes and nerves, we will class them as modificatory. 



4T9. What ? Describe Pig. 112. 4SO What is ? Describe Fig. 113. Can 

 the Thyroid Gland bo felt? 481. What are ? 



