"'Listen, young man,' he continued, folding his coat-tails closely about his legs--'try to reason it out: why should cats bite? Don't you know? I do.' "He looked at me anxiously. "'You take no interest in this problem?' he demanded. "'Oh yes.' "'Then why do you not ask me why?' he said, looking vaguely disappointed. "'Well,' I said, in desperation, 'why do cats bite?--hang it all!' I thought, 'it's like a burned-cork show, and I'm Mr. Bones and he's Tambo!' "Then he smiled gently. 'Young man,' he said, 'cats bite because they feed on catnip. I have reasoned it out.' "I stared at him in blank astonishment. Was this benevolent-looking old party poking fun at me? Was he paying me up for the morning's snub? Was he a malignant and revengeful old party, or was he merely feeble-minded? Who might he be? What was he doing here in Antwerp--what was he doing now?--for the bald one had turned familiarly to the beautiful girl in white. "'Wilhelmina,' he said, 'do you feel chilly?' The girl shook her head. "'Not in the least, papa.' "'Her father!' I thought--'her father!' Thank God she did not say 'popper'! "'I have been to the Zoo to-day,' announced the bald one, turning towards me. "'Ah, indeed,' I observed; 'er--I trust you enjoyed it.' "'I have been contemplating the apes,' he continued, dreamily. 'Yes, contemplating the apes.' "I tried to look interested. "'Yes, the apes,' he murmured, fixing his mild eyes on me. Then he leaned towards me confidentially and whispered, 'Can you tell me what a monkey thinks?' "'I cannot,' I replied, sharply. "'Ah,' he sighed, sinking back in his chair, and patting the slender hand of the girl beside him--'ah, who can tell what a monkey thinks?' His gentle face lulled my suspicions, and I replied, very gravely: "'Who can tell whether they think at all?' "'True, true! Who can tell whether they think at all; and if they do think, ah! who can tell what they think?' "'But,' I began, 'if you can't tell whether they think at all, what's the use of trying to conjecture what they _would_ think if they _did_ think?' "He raised his hand in deprecation. 'Ah, it is exactly that which is of such absorbing interest--exactly that! It is the abstruseness of the proposition which stimulates research--which stirs profoundly the brain of the thinking world. The question is of vital and instant importance. Possibly you have already formed an opinion.' "I admitted that I had thought but little on the subject. "'I doubt,' he continued, swathing his knees in his coat-tails--'I doubt whether you have given much attention to the subject lately discussed by the Boston Dodo Society of Pythagorean Research.' "'I am not sure,' I said, politely, 'that I recall that particular discussion. May I ask what was the question brought up?' "'The Felis domestica question.' "'Ah, that must indeed be interesting! And--er--what may be the Felis do--do--' "'Domestica--not dodo. Felis domestica, the common or garden cat.'