An experiment that ran for 151 days produced signals that suggested the presence of one of these constructs named after a holiday. That experiment is consistent with the proposed upper limit for the number of these constructs, which is one per 10-to-the-29 nucleons. (-5[1])The expression [read slowly] “2 q-sub-e q-sub-m all over h-bar c” must (15[1])be an integer in a physicist’s namesake quantization condition involving these constructs. (*) Dyons with no electrical charge are equivalent to these particles. To explain the topological properties of these particles, Dirac proposed his namesake “strings.” The existence of these particles does not (10[1])agree with Gauss’s law because the divergence (10[1])of the magnetic field (-5[1])would be non-zero. For 10 points, name these particles that only contain a (10[1])north or south pole, unlike (10[1])magnetic dipoles. ■END■