44 EVENINGS AT THE MICROSCOPE 



have passed two or three folds round him, we pass a tape 

 round the whole, with just sufficient tightness to keep him 

 from struggling. One hind- leg must project from the linen, 

 and we now pass a needle of thread twice or thrice through 

 the drapery and round the small of this free leg, so as to 

 prevent him from retracting it. 



Here then he lies, swathed like a mummy, with one 

 little cold foot protruded. Lay him carefully on the brass 

 plate, so that the webbed toes shall stretch across the glass. 

 Now, then, we pass another tape through the marginal 

 holes, and over the body, to bind it to the brass ; of course 

 taking care not to cut the animal, but only using just as 

 much force as is needful to prevent his wrigglings. Now 

 a bit of thread round each toe, with which we tie it to as 

 many of the holes, so as to expand the web across the 

 glass. A drop of cold water now upon the swathes to 

 keep him cool, and a touch of the same with a feather 

 upon the toes to prevent them from drying (which must 

 be repeated at intervals during the examination) and he 

 is ready. 



What a striking spectacle is now presented to us, as 

 with a power of 300 diameters we gaze on the web of the 

 foot! There is an area of clear colorless tissue filling the 

 field, marked all over with delicate angular lines, some- 

 thing like scales; this is the tessellated epithelium of the 

 surface. Our attention is caught by a number of black 

 spots, often taking fantastic forms, but generally somewhat 

 star-like: these are pigment cells, on which the color of 

 the animal's skin is dependent. But the most prominent 

 feature is the blood. Wide rivers, with tortuous course, 

 roll across the area, with many smaller streams meander- 

 ing among them; some pursuing an independent course 



