Figure 4.15. In this diagram is a long thin rectangle and a smaller one inside the larger one. The smaller one is at the bottom and centered left to right. It is approximately one third the width of the larger one and one half the height. Inside the smaller rectangle are rows and columns of circles that indicate holes. Outside the smaller rectangle but inside the larger one are rows and columns of dots indicating electrons. There is a connection on the left end of the larger rectangle labeled source. There is a connection to the bottom center, to the inner rectangle, that is labeled gate. There is a connection to the right end of the larger rectangle labeled drain. End verbal description.