 Scudder provides the additional detail that " instruments of all kinds were interdicted " , including any magnifying glass . After several hours Agassiz asks for a report and Scudder describes " the fringed gill @-@ arches and moveable operculum ; the pores of the head , fleshy lips and lidless eyes ; the lateral line , the spinous fins and forked tail ; the compressed and arched body . " Disappointed , Agassiz informs his student that he has failed to observe " the most conspicuous features of the animal " and commands him to " look again , look again ! " The mortified Scudder is eventually asked to consider overnight what he has seen , and is able to report to Agassiz the following morning that " the fish has symmetrical sides with paired organs , " which was the observation Agassiz was looking for . However , when Scudder then asked what he should do next , Agassiz replied , " Oh , look at your fish ! " which Scudder did for another two full days . 
