234 THE ORGANIZATION 



the left ventricle, the same from which it went out in its first 

 circuit. 



The organs of respiration are a windpipe and a pair of lungs. 

 The windpipe (f) opens (at e) at the root of the tongue, and 

 after passing backward a considerable distance, and in front of 

 the gullet, (g,) it forks into two branches, of which one goes to 

 the right and the other to the left lung. The lungs (I) are great 

 sacs divided into numerous, irregular compartments, like the in- 

 terstices of a sponge, in the thickness of whose meshes the mi- 

 nute arteries and veins pass and repass, to carry the blood from 

 and to the heart, during the process of aerification. 



The nervous system I have already stated to lie in a partially 

 overarched furrow upon the back of the spinal column. The 

 anterior part of it, the main organ, (en, cr,) is enclosed within the 

 cranium, (sk,) and consists of two great double masses, whose 

 halves lie symmetrically right and left of the median line of the 

 head. The anterior mass, the cerebrum, (en,) is by far the greater 

 of the two, and from it proceed the nerves of the two most deli- 

 cate senses, namely, sight (o) and smell (n). The posterior mass, 

 the cerebellum, (cr,) is completely overlapped by the cerebrum in 

 man, but projects beyond it in the monkeys and the groups 

 below them. The nerves of hearing and of taste (fig. 135, gn, c) 

 arise from the medulla oblongata, that part of the brain which 

 underlies the cerebellum (cr) and forms the immediate transition 

 to the main cord, (nr,) or spinal marrow, which joins it at the 

 base of the skull. The nerves which control the motions of the 

 body, the motory nerves, (fig. 135, - 2 ,) and the nerves of sensa- 

 tion, (g 1 ,) originate in pairs from the right and left sides of the 

 spinal marrow, (nr,) along its whole length. 



The reproductive organs lie symmetrically right and left of the 

 axis of the body, and consist of a pair of small, oval, egg-bearing 

 organs, the ovaries, (ov,) and two outgoing conduits (fl) which 

 unite in one common receptacle, the uterus (ut). When the 

 eggs are ripe, they drop from the ovary (ov) into the trumpet- 

 shaped mouth (fl) of the conduit, Fallopian tube, and thence are 

 conducted to the uterus (ut). There they undergo a change, 



