116 HALF-AN-HOUR 



(the food being passed on as it becomes reduced) to the first or 

 cesophagal portion of the intestine. Till this slide met my eye, I 

 had never seen any other preparation of the structure than one I 

 made amongst my first attempts, now some 30 years ago. Yet it 

 makes a most interesting, pleasing, and instructive slide. It 

 shrivels rather when mounted dry. The Gizzards of insects, 

 taken up as a systematic study, will furnish endless sources of 

 instruction and delight. Little has been published on the sub- 

 ject. Who will go in for them ? 



Cercopis sanguinolenta is a fine example of the class of 

 slides to which it belongs — entire insects. These, though not 

 altogether satisfactory to the student, are highly attractive, inter- 

 esting, and calculated to bring into the ranks of workers with the 

 microscope some who may have previously given such subjects 

 little thought. 



The antennas, three-jointed, should be carefully examined, the 

 facetted eyes, the forehead, the wings, the limbs, with their power- 

 ful claws and the terminal suckers, each having a tactile hair 

 distad in the centre. The robustness of the limbs, the number 

 and form of the tarsal joints, the curious and complex spurs on 

 the outer edge of the posterior tibiae, also at the distal ends of 

 the same joints, altertiately fixed and moveable^ the spurs at the 

 extremity of the first two tarsal joints in the same fimbs. All 

 these having a long tactile hair on the inner edge near their extre- 

 mity, these, with the spiracles, are the most noticeable facts to be 

 learnt from this valuable slide. The parts of the mouth are not 

 well seen, but one of the outer pair of four set^e, (a modified 

 mandible,) may be clearly made out; also, the three-jointed sheath 

 — case for surgical instruments, it may be called — or "promuscis." 



I had almost omitted to call attention to the fine set of saws 

 (two pairs) and their sheath, so well displayed. In considering 

 these, however, it should be remembered that they have been 

 displaced, the natural position being (for one side)^ as roughly 

 shown in Diagram, PI. XIV., Fig. 10. 



Ophion luteus (PI. XIV.). — This slide requires several hours 

 to master the details of structure with which we are presented in 

 it. I can only glance at them by a slight enumeration as follows : 

 — Tongue, parts of the mouth, antennae, wings with their hooks, 

 comb-like claws, and ovipositor. The tongue may be advan- 

 tageously compared with that of a wasp, and is strikingly different 

 from that of bees. The antennae show structure, described by 

 Dr. J. Braxton Hicks, which he supposes to be, from their 

 structure, an acoustic apparatus, and on very good analogical 

 grounds, it seems to me. The paper will be found in a volume of 

 " Linnaean Transactions " of a few years back, and marks a decided 

 advance in the knowledge of the subject. 



