104 EVENINGS AT THE MICROSCOPE. 



them, you will find them worth looking at. I dare say 

 you have never submitted them to half-an-hour's micro- 

 scopical examination. I have caught one with a spoon, 

 and put it into this narrow glass trough of water that it 

 may rest conveniently on the stage. 



We will take a cursory glance at its entire person. 

 Here is a flat, roundish head, a great globose, swpllen 

 thorax, and a long, slender, many-jointed body, ending in 

 a curious fork. But all is curious : — the head, with its 

 horny transparency ; its pair of rod-like antennae, covered 

 with minute points ; its two black eye-patches ; and its 

 jaws, beset with strong, curved hairs, set in radiating 

 rows, and, ever and anon, working to and fro with the 

 most rapid vibrations : the thorax, — so transparent, with 

 its amber-like clearness, that you can discern the dorsal 

 vessel, which contains the blood, ever dilating and col- 

 lapsing with the most beautiful regularity ; and beneath 

 this, the gullet, through which, now and then, descends a 

 dark pellet of food, to join the mass already lodged in 

 the stomach farther down, — a result, by the way, that 

 explains that incessant vibration and pumping motion of 

 the mouth-organs, which thus evidently are engaged in 

 collecting food from the water ; though, even with this 

 power, we can see no solid matter taken in, till we dis- 

 cern it agglomerated in the swallowed pellets : the body, 

 or abdomen, with its ten joints, all (with a slight excep- 

 tion) the counterparts of each other ; and each carrying 

 its own dilatation of the dorsal vessel, and its own portion 

 of the long and well-filled intestinal canal. All these, 

 I say, are very interesting and curious to observe ; espe- 

 cially when we select, as I have done, a young indi- 

 vidual for examination ; since the tissues then possess a 

 transluceney which is essential to our seeing with dis- 

 tinctness anything of the internal organisation, but 

 which soon gives place to opacity, as the insect advances 

 in age. 



