18. Where the number of names selected on the first drawing is not greater than the number provided in section 15, the sheriff shall draw a second card, note the number thereof and set it aside from the box. He shall then repeat the operation described in the third paragraph of section 17.
He shall repeat such operations until a greater number than that provided in section 15 is reached, and all the names corresponding to the last number drawn have been selected. However, he may, from the second drawing, stop selecting names if the number reached is at least equal to the number of polling subdivisions in the district.