310 EVENINGS AT THB MICKOSCOPE. 



Here it is. There is no protrusile proboscis, but the 

 throat is spacious, and capable of being everted to a 

 slight degree. The front border of the mouth is en- 

 larged so as to form a sort of upper lip, and this com- 

 bines with the wi'inkled muscular margin of the lower 

 and lateral portions to form the sucker. "With the dis- 

 secting scissors I slit down the ventral margin of the 



., sucker, exposing the whole 



-^ l^^ fiii^ iS""^*!. throat. Then, the edges 



i ^ ' '" jsfe^''* "d i ^sing folded back, we see 



\(»*'^^C'' < r^s,**5ii|-I implanted in the walls on 



^> ''^^ •' t''""*'^ ^'^^ dorsal region of the 



> I '^i' ^ 1^''^*/ / i^ cavity three white emi- 



X '. , * S^ nences of a cartillaginous 



"^ texture, which rise to a 



THKOAT OF lEECH lAiD OPEN. sharp cresceutic edge ; they 



form a triangular, or rather a triradiate figure. 



Now, if you recollect, this is the figure of the cut 

 made in the flesh wherever a Leech has sucked, as it is 

 of the scar which remains after the wound has healed. 

 For these three little eminences are the implements witli 

 Avhich the animal, impelled by its blood-sucking in- 

 stincts, effects its purpose. But to understand the ac- 

 tion more perfectly, we must use higher powers. 



I dissect out of the flesh, then, one of the white 

 points, say the middle one, and laying it in water in 

 the compressorium, flatten the drop, but use no more 

 pressure than just enough for that. JSTow I apply a 

 power of 150 diameters, and we will look at it in suc- 

 cession. Tou have under your eye a sub-pellucid mass, 

 of an irregular oval figure, and of fibrous texture, one 

 side of which is thinned away apparently to a keen 

 edge of a somewhat semi-circular outline. But along 



