624 



i) of Natural 



the fresh water. The Smelt is generally in 

 great request from its delicate and pecu- 

 liar flavour. Its well-known cucumber-like 

 smell is very powerful when they are first 

 taken out of the water. They are taken 

 both on our eastern and western coasts, and 

 are abundant in the Thames and Medway. 



The AMERICAN SMELT (Osmcrus virides- 

 cens) is considered a different species. The 

 body is long, green on the back, and silvery- 

 white on the sides. It inhabits the coasts of 

 New England, and as far as the Hudson, but 

 is unknown farther south. 



SMEW. (Mergus albetlus.-) This is a 

 web-footed bird, about the size of a VVigeon, 

 which seldom visits this country except in 

 very severe winters. It has a bill nearly 

 two inches long, of a dusky blue, thickest at 

 the base, and tapering into a more slender 

 and narrow shape towards the point. On 

 each side of the head is an oval-shaped black 

 patch, glossed witli green ; under side of the 

 crest black ; the other parts of the head and 

 neck white : the breast, belly, and vent are 

 also white, excepting a curved black line on 

 each side of the upper part of the breast, and 

 similar marks on the lower part : the back, 

 the coverts on the ridge of the wings, and 

 the primary quills are black ; the secondaries 

 and greater coverts tipped with white ; the 

 middle coverts and scapulars white ; and the 

 sides, under the wings to the tail, are varie- 

 gated and crossed with dark waved lines. 

 The legs and feet are of a bluish lead colour. 

 This species is easily distinguished from its 

 congeners by its black and white piebald 



HOOCEP SMEW. (MERUUS GOO OLI.ATUS.) 



appearance. Our figure represents a most 

 beautiful species, the HOODED SMEW (Mcr- 

 ffiis cucullutus\ which is common in North 

 America, but only accidentally found in 

 Europe. [See MERGANSER.] 



SNAIL. The Garden Snail (Helix asper- 

 sa\ and its allies, constituting the family 

 Helicidce, are closely allied to the Slugs in 

 organization, and differ from them in little 

 else than in their being inclosed in a shell, 

 which is univalve, spiral, sub-pellucid, and 

 brittle, and has a semilunar aperture. Its 

 head is furnished with four tentacula ; on 

 the superior pair the eyes are placed ; while 



the inferior pair have no visual organs, but 

 seem more exclusively adapted to the per- 

 ception of tactile impressions. Both the 

 upper and lower tentacula are retractile, and 

 can be completely inverted so as to be with- 

 drawn into the interior of the body. Each 

 tentacle is a hollow flexible cylinder. When 

 partially retracted, the extremity of the or- 

 gan is drawn inwards, and two cylinders are 

 thus formed, one within the other : if the 

 outer cylinder is elongated, as in protruding 

 the tentacle, it is at the expense of the inner 

 one ; and, on the contrary, the inner cylin- 

 der, when the organ is retracted, is length- 

 ened as the other becomes shorter. Snails 

 lay eggs, and carefully bury them in the 

 ground. These eggs are very numerous, 

 round, semi-transparent, about the size of a 

 small pea, and covered with soft shells : they 

 are also united to each other by an imper- 

 ceptible slime. When the Snail leaves the 

 egg, it is observed with a very small shell on 

 its back, having only one whorl ; but, in 

 proportion as it grows, the shell increases in 

 the number of its spiral turns. The addition 

 is always at the mouth, the first centre still 

 remaining ; the animal sending forth from 

 its body that slime which hardens into a 

 calcareous substance, and is still fashioned 

 into similar convolutions. Thus fitted with 

 its covering, which is light and firm, the 

 Snail finds itself well defended from external 

 injury ; and it has only to retire iuto its 

 fortress to escape impending danger. It de- 

 lives its chief subsistence from the leaves of 

 plants and trees, and, although very vora- 

 cious, is extremely delicate in its choice. 

 When in quest of food, it moves forward by 

 means of that broad muscular skin, which 

 is sometimes seen projecting beyond the 

 mouth of the shell : this is expanded before, 

 and then contracted with a kind of undu- 

 lating motion. It is also able to ascend in 

 a perpendicular direction, and has its pro- 

 gress facilitated by means of that viscous 

 excretion which it emits whenever it moves. 

 On this glutinous matter it can proceed 

 slowly and in safety along a rugged path, 

 or ascend trees and fences for the purpose 

 of feeding ; and it also descends by the same 

 aid, without danger of falling and injuring 

 its shell. 



At the approach of winter the Snail buries 

 itself in the earth, or retires to some hole, 

 where it continues in a torpid state during 

 the severity of the season : thus it sometimes 

 lies torpid for six or seven months, till the 

 genial warmth of spring awakens it to a 

 state of activity ; when it quickly makes 

 amends for its long abstinence by feasting 

 on every vegetable substance that falls in its 

 way. Before, however, they commence this 

 inactive state of existence, Snails close the 

 mouth of their shells with an epiphragma 

 (or covering, not attached to or forming a 

 part of the animal), which, stopping it up 

 entirely, protects it from every external in- 

 jury : it is composed of a whitish substance 

 somewhat resembling plaster. In the centre 

 is an exceedingly minute orifice, communi- 

 cating with the lungs ; and this minute hole, 

 though not large enough to admit a drop of 

 water, is of sufficient capacity for the pas- 



