 Cope was described by zoologist Henry Weed Fowler as " a man of medium height and build , but always impressive with his great energy and activity " . To him , Fowler wrote , " [ Cope ] was both genial and always interesting , easily approachable , and both kindly and helpful . " Cope 's affability during visits to the Academy of Natural Sciences to compare specimens was later recalled by his colleague Witmer Stone : " I have often seen him busily engaged in such comparisons , all the while whistling whole passages from grand opera , or else counting the scales on the back of a lizard , while he conversed in a most amusing manner with some small street urchin who had drifted into the museum and was watching in awe with eyes and mouth wide open . " His self @-@ taught nature , however , meant that he was largely hostile to bureaucracy and politics . He had a famous temper ; one friend called Cope a " militant paleontologist " . Despite his faults , he was generally well liked by his contemporaries . American paleontologist Alfred Romer wrote that , " [ Cope 's ] little slips from virtue were those we might make ourselves , were we bolder " . 
