AT THE MICROSCOPE. 115 



These facts I have been able to make out in the cast skin of a 

 small Hemipteron (" The Sage-fly "). 

 Figs. 4 and 5. — Represent the joints composing a limb, L3 =one of the 

 third pair of the left side. At the knee-joint is a curious 

 pulsating organ, po., in Figs. 4 and 5 — of course, only to be 

 seen in living specimens ; pv. , pulvillus, a sucker at the end 

 of the tibia, whereby aphides are able to ascend smooth sur- 

 faces against gravity. In Fig. 4, the seven joints of the leg 

 are numbered. 



Lower Half. 



Fig. 6. — Larva of Caddis-worm, Leptocera. The segments composing 

 the body are indicated by the numbers 1 — 13 respectively. 

 The mandibles are strong, obtuse at the tip, with several 

 short teeth fitted for gnawing vegetable matters, of which 

 the capacious stomach and intestines are seen to be full. The 

 maxillae and labium are rudimentary. The head exhibits no 

 trace of antennae ; the eyes very small and difficult to see. 

 b.f. supposed to be branchial filaments, but on examining 

 living specimens, I find (in them) just a remarkable fringe of 

 black hairs, separating the gills into two pairs seated above 

 and below this line ; of these gills I can see no trace in the 

 mounted specimen. 



,, 7. — Ihr., labrum ; md, mandible of left side. 



,, 8, 9. — First and third limb of left side ; 1 — 7, the joints compos- 

 ing the limb. 



,, 10. — Hook of the left side = a rudimentary abdominal limb, 

 attached to the last (13th) segment ; d. , dorsal plate of this 

 segment. 



Plate XXXL 

 Figs. 1 and 2. — Acari from Chaffinch, ^ and ^ . 



Fig, 3. — Organ of Sand- Wasp, (a copy of engraving in Science Gossip, 

 referred to by Dr. George:) — a. a., described as the double 

 sting ; b.h., tubes ; c. , sheath. 

 ,, 4. — Foot of the same insect. 



The above Plates, except where otherwise stated, are from drawings 

 by Mr. Tuffen West. 



