The link in the text: "See Bipolar junction transistors, Ch 2 for more details.". Doesn't work.
See: http://www.allaboutcircuits.com/vol_3/chpt_4/3.html#03084.png
See: http://www.allaboutcircuits.com/vol_3/chpt_4/3.html#03084.png
***********Here I'm assuming the use of a multimeter with only a single continuity range (resistance) function to check the PN junctions. Some multimeters are equipped with two separate continuity check functions: resistance and “diode check,” each with its own purpose. If your meter has a designated “diode check” function, use that rather than the “resistance” range, and the meter will display the actual forward voltage of the PN junction and not just whether or not it conducts current.