Otis Robinson Bacheler, Popular Science Monthly (1879)
“ Change of form seems to be quite under control, and change of color appears to be so at times. Their intelligence seems to be of a very low order. After being separated they greet one another with open mouth and a hiss. They manifest no emotion, and no form of petting seems to be appreciated. Their instinct is to conceal themselves from observation, to climb to the highest available point, and to lie with open mouth waiting for their prey to come to them. The only activity they manifest is in the use of the tongue, and in this they are not excelled by any other animal. ”
