HARD WICKE'S SCIENCE- G OS SIP. 



109 



undoubtedly organs of sense). They cover a large 

 portion of the mouth, which is somewhat conical in 

 form and its profile is not a bad miniature represen- 

 tation of a parrot. 



Mr. Walker gives a description of this genus in his 

 " Insecta Britannica Diptera," vol. i. page 220, as 

 follows: "Palpi protruded, oval, very large in the 

 male. Proboscis shorter than the head, conical, 

 somewhat compressed, incurved towards the pro- 

 sternum, receding from the palpi, and armed at the 

 tip with a short spine (the projecting extremity of 

 the tongue)." 



A careful dissection of the mouth of this creature 

 shows there are three such spines, that they are 

 veritable jaws, and that they operate quite inde- 

 pendently of the tongue. Two of these jaws are 

 situated above, and are shorter than the single lower 

 one which usually projects beyond the tongue. The 

 single lower jaw has a vertical motion, and as it 

 works between the two upper ones a slightly horizontal 

 movement is communicated to them. Both these 



similar particles- What useful purpose (if any) it 

 can serve in the economy of nature, in the narrow 

 strip of littoral to which it limits its movements, is 

 a question I must leave to those curious on such 

 points. To me it remains a mystery ; but that it 

 is well adapted for the position it occupies there can 

 be little doubt left on the mind of any one who has- 

 watched its movements or studied its mouth organs. 

 Cardiff. 



ON THE FORMATION OF AN LNSEC- 

 TORIUM OR INSECT VIVARIUM FOR 

 THE EXHIBITION AND STUDY OF 

 LIVING TROPICAL INSECTS. 



By George S. Parkinson. 



N the early days of the Royal Aquarium, 1875, 

 when it was about to be started as a scientific 

 resort, it occurred to the writer to submit a sugges- 

 tion which met with a ready response, and he was 



I 



Fig. 58. — Proposed tropical insect vivarium. 



upper jaws are furnished with an enlargement on their 

 incurved sides which comes in contact with depres- 

 sions on the lower jaw, and proves an effective piece 

 of machinery for seizing and crushing food. Imme- 

 diately above the upper jaws is a region armed with 

 imbricated chitinous points ; these continue the 

 process of mastication, while two lobes of the 

 tongue (similarly armed with still finer points) com- 

 plete the process. 



I have little doubt some portion of the food of this 

 creature, in its perfect state, consists of the tender 

 alga;, as small fragments are sometimes found attached 

 to the labrum, and the stomach also appears to contain 



requested to write out his views, with the object of 

 forming an exhibition of living tropical insects. 



This done — when the great expenses attending the 

 building of the Aquarium became a hindrance to 

 further progress, and beyond the adoption of the 

 word, then first suggested, " Insectorium," as a 

 simple and popular appellation, and which was used 

 to distinguish a few glass cases, a very poor and 

 most unsatisfactory result — the matter came to a 

 standstill, so far as living insects were concerned. But 

 as a resulting consequence, in 1878 a very beautiful 

 exhibition of dead insects, under the title of "The 

 Great National Entomological Exhibition," and the 



