From Nature Stories from Darwin:
Among Darwin’s pet dogs was a large black and white half-bred retriever. This animal was the delighted companion of the naturalist in his walks about the home and neighborhood. Bob, for this was the dog’s name, had but one fear in the jaunts which he took with his master. This fear was that the walk would be too short.
When the pair started out, Bob generally led the way, and he was an elated leader. Stepping high, with head much raised, erected ears, and tail carried aloft, but not stiffly, he was the picture of four-footed pleasure.
But Darwin was interested in living things besides dogs. Not far from the residence was a hot-house, where the naturalist cultivated plants for experimental purposes. This was reached by a path which branched to the right, near the dwelling. When Darwin would turn down this path, Bob showed disappointment to the point of dejection, for his dog mind made him fear that the hot-house would really be the end of the walk. The instantaneous and complete change in Bob’s expression formed one of the naturalist’s favorite studies of the emotions in animals. So alert was the dog that any swerving of his master towards the hot-house brought on the symptoms of dejection. It worked the same when an inclination to turn down the path was shown, simply to experiment with Bob’s emotions. When this feeling came the ears fell to the side of the head, the attitude of the whole body changed and the eyes lost their sparkle. The case of Bob became so well known to all the Darwin family that he was called by them the dog with the “hot-house face” (pg 45-47).
I’ve seen this hot-house face before:
