54 REPTILES AND BATRACHIANS. 



of water descended suddenly, then Froggin in one leap was far 

 away. He was as sensitive as a snake to vibrations through the 

 ground, such as anything being dragged, or let down suddenly. 

 His especial delight during the summer was to luxuriate under 

 some moss in a pan of water. Here he would remain all day, 

 with only his two little specks of nostrils on the tip of his snout 

 visible, and so indistinct were they that often one could only 

 discover him by seeking him. 



That frog did not reciprocate the exigencies of science, or the 

 spirit of inquiry which led to his rather too frequent molestation. 

 The forcible examination of his fingers, toes, tongue, etc., seemed 

 to frustrate the taming process. Unmolested for a few days, and 

 with the remembrance of a yesterday's feast, he wore a very 

 different expression to that with which he greeted his recent 

 tormentor ; yet if he were in his usual corner on the morning 

 visit he did not attempt to escape; and if he were not there, 

 familiar sounds — and he recognised my voice — would invite him 

 from some nocturnal retreat, when he gradually made for his corner, 

 faced about, backed himself as far as practicable into the crevice, 

 and thence watched proceedings. Notwithstanding this sign of 

 confidence, his varying expression was unmistakable. Haunted by 

 yesterday's dental examination, he scowled up from under his 

 eyelids, and suspiciously watched an approaching hand. At other 

 times he would look up brightly, as also did the Froggies, as if to 

 say, "Well, what have you got for us ?" The changes of expres- 

 sion were unmistakable and yet perplexing, as one does not look 

 for emotional sentiments in frog physiognomy. But Claus threw 

 light on this phenomenon also. " In Batrachians there is a 

 retractor muscle, by means of which the large bulb of the eye can 

 be drawn back." Further observation, therefore, may show us 

 that a sense of fear or displeasure causes this retraction of the eye- 

 ball, and that varied expressions may really be witnessed in the 

 face of a frog, and the appearance of " scowling " was one result. 

 I observed the same in the small frogs, and also in the toad ; but 

 the latter is of a more imperturbable temper, less excitable, and 

 the expression of its eye is habitually contemplative and unresent- 

 ' ful. Both have large prominent eyes capable of a wide range of 

 vision, and by the movement of the pupil can take side-long 

 jdlances without turning their heads. Indeed they never do turn 

 their heads, having no neck, — no cervical vertebra, — but the 

 motion up and down of the head is frequent. The eye is not 

 buried in an orbit, as our own, but is only framed by the bone, as 

 may be seen by the large round spaces in the skeletons (p. 59), 

 and also that of the salamander (p. 71). If you look into 



