text:  Now Mr Shaw's discovery in relation to these matters is in a manner twofold; first--he ascertained by a lengthened series of rigorous and frequently-repeated experimental observations that parr are the early state of salmon being afterwards converted into smolts; secondly --he proved that such conversion does not under ordinary circumstances take place until the second spring ensuing that in which the hatching has occurred by which time the young are _two years old_