THE YOUNG NATURALIST. 



79 



>en out at the tail, and it is thus enabled to 

 eathe the atmospheric air. When the larva of 

 e gnat was first discovered, a drawing was made 

 it and it was given to an artist to put upon wood 

 p the engraver. The artist mistook the round 

 orax for the head and thought it wanted ex- 

 ession, so he drew it thus : 



hen after a while that was given to another 

 list to copy from one book into another (a thing 

 hich is too frequently don°), and he thought it 

 anted still more expression and drew it thus : 



■om the larva the gnat turns to a pupa, and 

 ter remaining a short ti me in that state, assumes 

 e perfect or winged form. I have many times 

 :en asked if the gnat was of any use to man, and 

 most certainly is. If you go along the banks of 



. e Thames at low wateryou will see that it is of a 

 ddish color, and if you throw in a stone a blac k 

 .tch will make its appearance by the mud in the 



. )ttom being disturbed, which after a time will 

 ttle and the water will assume its original red 

 lor. If you skim the surface of this water into 



. glass, you will find that there are millions up in 

 illions of the larvae of the gnat, which are feeding 

 )on the refuse matter of our bodies, and which, 

 not destroyed, would cause horrible diseases, 

 ch as typhoid fever. I hope by this time I shall 

 ive succeeded in inducing some of you to appre- 

 ate some of those insects I have mentioned, a 

 :tle more than you have hitherto done. 



CONCHOLOGY. 



MONGST the many objects of Natural History 

 ^rounding us on all sides, Shells are general 

 vorites. Numbers of them are gathered every 

 ?ar by visitors and residents at the seaside, and 

 'e taken home ; some to be studied, classified and 

 ranged in cabinets ; more, however, to be thrown 

 »vay or lost ; or at the best, preserved only for the 

 ike of their graceful forms and delicate tints ; 

 ithout any attempt on the part of the possessor 

 ) learn even so much as their names. 

 Few branches of Natural History can be more 

 ;adily studied, or possess greater interest than 



Conchology, while the specimens require little or 

 no preparation to fit them for the cabinet, and 

 they do not need the same watchful care to guard 

 them from decay and destruction which Entomo- 

 logical and some other collections, from their 

 nature demand. 



It is not my object now, however, to say more 

 to those who have opportunities of collecting Shells 

 at the sea shore than to urge them not to stop 

 short at collecting merely, but to classify and 

 arrange the specimens obtained, and, above all, 

 to study, not the shells alone, but the living 

 animals which inhabit them. But there are many 

 who have only rare opportunities of visiting the 

 sea-side, and probably very few of the young people 

 so situated have ever thought that they could 

 collect shells and study them in their inland homes. 

 This was my own case. I had collected shells 

 for many years at the seaside, but had made no 

 attempt to classify them, and it was only when at 

 length I resolved upon doing so, and began to 

 consult books on the subject, that I learned how 

 many Land and Fresh-water Shells there were of 

 which I had, with one or two exceptions, hitherto 

 known nothing. There is not among these the 

 beauty of coloring and variety of species that are 

 to be found in sea shells ; still, they are well worth 

 the trouble of collecting, and will give an interest 

 to many a country ramble, and employ, both 

 pleasantly and instructively, many a leisure hour^ 

 There is scarcely a stream or pond in which some 

 species of fresh water molusc may not be found, 

 while land shells may be found on every hedge 

 and bank, in every wood or garden. There is 

 much to admire in their graceful shapes, and it 

 will be found exceedingly interesting to observe 

 the habits, form and structure of the different 

 : kinds. They should of course be taken, and kept 

 for a time, alive, that this may be done. 



My object in writing these few lines is to induce 

 | some of the readers of the Youn« NATURALIST 

 I to take up this branch of Natural History, To 

 beginners the apparent magnitude of any subject 

 i to which they may be attracted often deters them 

 ! from making a beginning ; here is a study for 

 | them, presenting few difficulties and of limited 

 extent. When they have acquired a knowledge 

 I of the land and fresh water shells, they need not 

 stop there, but, as opportunity offers, can add to 

 their collection the more varied species of sea 

 : shells which they may be able to obtain. — H.T.R. 



