THE YOUNG NATURALIST. 



61 



roduces a two-winged fly, in science Diptera. 

 'he second form of pupa differs much from these, 

 nstead of being a hard case, enclosing, as in 

 n egg-shell, the whole of the insect that will 

 ventually emerge, it consists of a very compound 

 ase, every organ, legs, wings, antennae, &c., 

 eing enclosed in separate sheaths. These are 

 ailed Xecromorphjus pupa;. Three different 

 lasses of insects are produced from Xecromorphou* 

 Jupae. First Hymeaoptera, the order that includes 

 \'a>ps and Bees, Ants, Ichneumons, and many 

 • ther interesting species. Second Trichoptera, of 

 diich the best known will be the Caddis Fly. 

 1 'hird Culeopti r.t, or Beetles. The third kind of 

 i upae is called Isomorphous, and differs again from 

 ■he two preceding forms. They appear, as their 

 { ame implies, to be intermediate between the larva 

 I nd the imago. They move about freely, have' 

 | le free use of their limbs, aad also devour food, 

 I Ifhich is not the case with the other two. But for 

 ie absence of wings some of them might be 

 iiistaken for the perfect insect. The first class of 

 isects produced from Isopiorphous pupae is 

 j Feuroptera, or nerve-winged insects, of which the 

 )ragon Fly is a well-known type. The second is 

 rthoptera, or straight wings, which includes a 

 iriety of well-known species. The Cockroach, 

 | it domestic pest, belongs to this class, as do the 

 j arwig, Grasshopper, Cricket, and others. The 

 I lird is Hcmiptcra, or half-wings. Plant-lice, 

 lant-bugs, and other similar insects, belong to 

 I lis class. 



It will be seen that there is an approach to 

 >rrectness in this classification, but it is open lo 

 ejection. For instance, the Caddis Fly and the 

 >ragon Fly are so very nearly allied that some 

 aturalists include both in one class — A T europtera. 

 [ost of Lepidoptera have Amorphous pupae, but 

 >me few amongst the Tvneina and the Zygenidce 

 ive A r ccromorphous pupae. Other discrepancies 

 ight also be found, but probably no general law 

 m be laid down in Nature to which there are not 

 xeptions. 



In preparing for the final change, those larvae 

 at produce Amorphous or Xecromorphous pupae 

 low an amount of foresight, or instinct, that is 

 uly wonderful, and is yet absolutely necessary for 

 e preservation of the species. The object to be 

 tained is that when the imago emerges it shall 

 ; so situate that it can escape safely. Butterflies, 



Moths, Szc, need a place where they can remain a 

 few minutes with their wings hanging clown, that 

 they may expand and become rigid. The pupae 

 of many Butterflies are suspended by the tail, some 

 having, in addition, a belt of silk round the body. 

 The pupae of but few Moths can be hung up, but 

 many are enclosed in silken cocoons placed in such 

 situations as will ensure safe emergence ; some are 

 left in rolled-up leaves, others on the surface of 

 the ground, or below it at various depths. The 

 cocoons of some species are so hard that they are 

 not easy to cut with a knife, yet the soft flaccid 

 Moth that comes out of the pupa is able to break 

 through with ease, and will dry and harden its 

 wings when it gets through. Those that are buried 

 in the ground, work themselves up to the surface 

 when ready to emerge, and generally leave the 

 pupa-case protruding. So with those that pass 

 the earlier stage in tree trunks, reed stems, &C., 

 they force the. pupa-case through the bark, and 

 leave it sticking there. In some of those species 

 whose earlier stages are spent under water, the 

 act of emerging from the pupa is attended with 

 much risk. In the Gnat, for instance, the pupa 

 is made to float on the surface of the water before 

 the insect emerges. The pupa case splits on the 

 upper surface, and the insect draws itself partly 

 out. Another effort or two, and it is free ; but if, 

 at any moment before it is at liberty, its frail bark 

 is capsized, or the ripples wash over it ever so 

 slightly, the result is fatal, and the insect perishes. 

 The pupa of the Dragon Fly climbs out of the 

 water before the insect emerges. 



Space will not permit us enlarging on this hea 1 

 Next week we will speak of the perfect insects. 



LANCASHIRE & CHESHIRE 

 ENTOMOLDGICAL SOCIETY. 



The November Meeting of this Society was held 

 November 24th, at the Free Public Library raid 

 Museum, Liverpool. The Vice-President, 

 Mr. Benjamin Cooke, occupying the chair in the 

 absence of the President. Mr. Cooke referred O 

 the death of one of our highly esteemed members 

 — Mr. Noah Greening, late of Warrington. A 

 paper on "Apterous Lepidoptera," was read by 

 the Hon. Secretary (Mr. W. E. Sharp). After 

 some little discussion on the subject of the paper, 



