HABITS AND FACULTIES. 15 



The slugs possess, in a remarkable degree, the power of elongation 

 and contraction of the body. When fully extended, it is long, narrow, 

 more or less cylindrical, and generally terminating in a sharp point. 

 The carina of the carinated species disappears. The head is protruded 

 far beyond the mouth ; the eye-peduncles are long, slender, and grace- 

 ful. The mouth is changed from an oval to an elongated form, with 

 parallel sides and rounded ends. The glands are lengthened, lose their 

 prominence, and appear nearly smooth. But when alarmed by the 

 touch of a foreign substance, an instant change occurs, and a sudden 

 contraction takes place. The eye-peduncles and tentacles are retracted 

 and the head is drawn under the mantle. The anterior edge of the 

 mantle is brought to the level of the foot, and its form becomes nearly 

 circular. The body is shortened to one fourth of its former length, and 

 tumid ; the back is rounded and rises high in the centre, and the skin 

 is rough with prominent glandular protuberances. The carina, when it 

 exists, becomes conspicuous. This is the form which they assume in 

 their retreats when they retire to protect themselves from the effects 

 of drought and cold. It differs so much from their form when in 

 motion, that one not well acquainted with them would hardly recognize 

 the same animal in its new shape. It is among the Limaces, perhaps, 

 that the change is most striking, and the difference of form between 

 the extremes the greatest. 



The slugs commence reproducing their kind as early as the end of 

 the first year, before they have attained their full dimensions, and 

 hence the eggs of the same species often vary considerably in size. 

 These are deposited in a cluster of thirty, or thereabouts, in the soil 

 and in other moist and protected situations ; or if the species be one 

 that frequents houses, then in the crevices or corners of the walls or 

 under the decaying planks of cellars. In general form and appearance 

 they resemble the eggs of the shell-bearing genera, but differ from them 

 in several important particulars. The eggs of the snails are all opaque, 

 while those of the slugs are more or less transparent, permitting, in the 

 Limaces, a view of the cicatricula, and affording an opportunity of ob- 

 serving its developments. Those of the former are all deposited free, 

 or unconnected, except by a slight agglutination; those of the latter, in 

 some of the species, are connected together by a prolongation of the 

 outer membrane at their longest diameter, thus forming a sort of 

 rosary. In other species they are deposited in a mass. The deposits 

 of eggs, when made, are abandoned by the slug, who then removes to 



