with reference to Horticulture. 347 



On the'right side, or neck, of the slug and snail there are three 

 apertures. " The largest, which is the respiratory orifice, is situ- 

 ated at the edge of the shield : the second is at the posterior 

 and upper margin of this first orifice ; it is the anus : the third 

 is either placed directly under the pulmonary opening, or imme- 

 diately ^behind the upper tentaculum; it is the exit for the organs 

 of generation." {Nunnely.') 



The skin is soft, and lubricated with a viscid mucus, which is 

 secreted most copiously when the animals are in motion, and, 

 running down on the ground, it serves to smooth the way, and 

 leaves a glistening track behind, which may lead to the discovery 

 of their retreats. They are strictly gasteropodous, crawling at a 

 slow pace on the flat sole which constitutes their foot and belly. 

 This foot is very muscular, and all its fibres aid in the act of 

 locomotion ; but progression is principally performed by a pair 

 of muscles which extend from the tail to the fore part, running 

 along the middle of the^foot. On opening the cloaks, they are 

 seen projecting on the interior surface of the foot as two raised 

 lines, larger before than behind. By putting a slug into a bottle 

 partly filled with water, the regular contractions^of these longi- 

 tudinal muscles may be distinctly seen, recalling to recollection 

 the apt comparison of Swammerdam — " following each other 

 like the waves and billows of the sea." 



These animals are hermaphrodite and oviparous. They de- 

 posit their eggs under clods of earth, loose stones, or in the 

 ground, in which the parent digs with its foot a circular hole, 

 about 1 in. deep. The eggs vary from twelve to thizty in 

 number; they are white, oval or round, about the size of a com- 

 mon shot, with a smooth soft skin, which is entirely membranous 

 in the slugs, but in the snails contains innumerable minute cal- 

 careous grains always in a crystalline state, and usually of a 

 rhomboidal figure. They are, in ordinary seasons, hatched in 

 about three weeks after being laid, but the time is regulated 

 much by temperature, so that in cold seasons it is greatly re- 

 tarded. The young issue from the egg in the likeness of their 

 parents, active, and furnished with every organ; and the young 

 snails have even then a shell fitting their size and strength. 



To what length of years the life of a snail or slug is prolonged 

 has not been determined. From our own observations, we con- 

 clude that the shell of the snail is usually completed before the 

 termination of the second year, when the animal may be said to 

 have reached maturity. It is a gross error to suppose that the 

 marks on the shell, which indicate the successive stages of its 

 growth, indicate also the tenant's age ; every space between 

 two such marks being said to be formed in one season. This is 

 not the case. These creatures are very patient of injury, recover- 

 ing after the cruelest wounds; and they are capable of repairing 



