The snail carries its eyes in telescopic watch-towers. This animal is, for the most part, nocturnal in its habits, and, since prominent and commanding view points are assigned to its organs of sight, one would naturally expect to find a comparatively high degree of development in them; and this supposition is correct. The eyes of the creature are in the extreme tips of its "horns," and consist of (1) a cornea, (2) a lens, and (3) a retina. Lubbock is rather disposed to decry the visual powers of the snail;[10] my conclusions, drawn from personal observations, are, however, directly the opposite. The position of the eyes at the extreme tips of the horns naturally indicates that they subserve a very useful purpose; otherwise they would not have attained such prominence and such a high degree of development. Actual experimentation declares that the garden snail can see a moving white object, such as a ball of cotton or twine, at a distance of two feet. In my experiments I used a pole ten feet in length, from the tip of which a white or dark ball was suspended by a string. The ball was made to describe a pendulum-like movement to and fro in front of the snail on a level with the tips of its horns. Time and again I have seen a snail draw in its horns when it perceived the white ball, to it an unknown and terror-inspiring object. I have likewise seen it change its line of march, and proceed in another direction, in order to avoid the mysterious white stranger dancing athwart its pathway. Dark-colored objects are not so readily perceived; at least, snails do not give any evidence of having seen them until they are brought within a foot of the creatures under observation. A snail will generally see a black ball at twelve or fourteen inches; sometimes it will not perceive the ball, however, until it has been brought to within six or eight inches of its eyestalks. During the season of courtship snails easily perceive one another at the distance of eighteen or twenty inches. I have often watched them at such times, and have been highly entertained by their actions. The emotional natures of snails, as far as love and affection are concerned, seem to be highly developed, and they show plainly by their actions, when courting, the tenderness they feel for each other. This has been noticed by many observers of high authority, notably Darwin, Romanes, and Wolff.[11] Mantagazza, a distinguished Italian scientist, in his _Physiognomy and Expression_, writes as follows: "As long as I live I shall never see anything equal to the loving tenderness of two snails, who, having in turn launched their little stone darts (as in prehistoric times), caress and embrace each other with a grace that might arouse the envy of the most refined epicurean."[12]