text:  As no experimental observations regarding the future dimensions of the _detenus_ of the ponds could be regarded as legitimate in relation to the usual increase of the species (any more than we could judge of the growth of a young English guardsman in the prisons of Verdun ) after the period of their natural migration to the sea and as Mr Shaw's distance from the salt water--twenty-five miles we believe windings included--debarred his carrying on his investigations much further with advantage he wisely turned his attention to a different though cognate subject to which we shall afterwards refer