36 



THE MUSEUM. 



their size and weight in a week. The 

 earliest hatched young of the season 

 generally attain their full maturity be- 

 fore the end of the first year, although 

 they may afterwards increase some- 

 what in bulk. Those which leave the 

 egg at a later period mature during the 

 second year. Individuals kept in con- 

 finement and fully fed reach a much 

 greater size than when in their normal 

 condition. They possess in a remark- 

 able degree the power of elongation 

 and contraction of the body. When 

 fully extended it is long, narrow, more 

 or less cylindrical, and generally term- 

 inating 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 graceful. The mantle 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 contrac- 

 tion 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 its former length 

 and tumid; the back is rounded and 

 rises high in the center, and the skin 

 is rough with prominent glandular pro- 

 tuberances. The carina, when it exists, 

 become 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 ac- 

 quainted with them would hardly re- 

 cognize the same animal in its new 

 shape. It is among the Limaces, per- 

 haps, that the change is most striking 

 and the difference of form between the 

 extremes the greatest 



They 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 consider- 

 able 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 de- 

 caying planks of cellars. In general 

 form and appearance they resemble 

 the eggs of the shell-bearing genera, 

 but differ from them in several impor- 

 tant particulars. The eggs of the snails 

 are all opaque, while those of the slugs 

 are more or less translucent, permit- 

 ting in the Limaces a view of the cica- 

 tricula, and affording an opportunity 

 of observing its developments. Those 

 of the former are all deposited free or 

 unconnected, except by a slight ag- 

 glutination; those of the latter, in some 

 of the species, are connected together 

 by a prolongation of the outer mem- 

 brane at their longest diameter, thus 

 forming a sort of rosary. The depos- 

 its of eggs, when made, are abandoned 

 by the slug, which then removes to 

 some other convenient place. A con- 

 siderable number of separate deposits 

 are made during the year. 



Nature Study. 



We are coming to a day when the 

 importance of the study of Nature is 

 beginning to be recognized. In many 

 of the Normal Schools instructors in 

 "Nature Study" are already employed, 

 at teachers' institutes "Nature Study" 

 is becoming a common topic for the 

 lecturers, and in academies and colleges 

 collections are being made, and mus- 

 eums established. Although many of 

 the lectures, and not a few of the in- 

 structorships give evidence of attempt- 

 ing to carry on a large business upon a 

 small capital, and although the col- 

 lections are for the most part entirely 

 unorganized and in snch a chaotic 

 state that the instructors can make but 

 little use of them, they prove that there 

 is a growing desire— vague though it 

 may be — for more thorough and sys- 



