250 EVENINGS AT THE MICROSCOPE. 



f?ecal matter of a yellowish-brown colour is collected in 

 two small masses, near the extremity. Along the under 

 side runs the ovary, which in this specimen contains two 

 long oval eggs in advanced development; from their 

 transparent brightness, I suspect the young are produced 

 before birth. I think I can detect a contractile bladder, 

 but am not certain. 



The dorsal region of the trunk is marked with strong 

 rugged lines running longitudinally; these look like corru- 

 gations of the integument, but I incline to think them the 

 strongly developed muscles for the retractation of the foot. 

 Muscles are seen running through the joints of the foot, 

 until they can no longer be traced, from their tenuity. 

 The viscera can be detected with difficulty, partly owing 

 to the longitudinal muscles, which are so strong and close, 

 and partly from the incessant contraction and elongation 

 of the parts, which drive the internal organs hither and 

 thither. It refuses, you see, to swallow carmine, which 

 might have assisted us. 



This singular animal is lively in its motions, especially in 

 the protrusion and retractation of the extremities. These 

 are constantly alternating, and a very curious sight it is to 

 see the immense length of foot suddenly thrust forth from 

 the body, in which it has been completely hidden, the 

 starting out of the horizontal processes, and the diverging 

 of the long toes, as these are successively uncovered. The 

 latter do not seem to be often used as instruments of pre- 

 hension or adhesion. Indeed, the animal does not appear 

 very much given to change of place, but lies in the water, 

 alternately contracting and elongating. Frequently, as the 

 foot is thrust out, the body is made to bend forward so as 

 to form a right angle (see the engraving, in which the 

 animal is thus represented at a ; b represents it when the 

 head is rotating, but the foot is almost wholly withdrawn 

 within the body ; in which state the resemblance to a 

 telescope, or to a nest of glass tubes, is striking). 



