Amendments of the principal Act concern interpretations, powers of the Minister to make by-laws, saving for Acts done for artificial propagation, scientific purposes or improvement of fisheries, qualification of conservators, the Salmon Conservancy Fund, use of nets, dealing in salmon, powers of inspection and detention on sea fisheries protection officers, etc. The Minister may by bye-law authorize, subject to such conditions as he thinks proper, the placing, erection, fishing with and use of a