By the Rev. J. E. Vize. 



89 



shell ; thus it is formed, like ours, of continual readditions from 

 within. If ever a Paludina vivipara should be obtained, as it 

 produces its young alive, and has them during the warm season in 

 every stage, from the fully developed young one down to the 

 minute gelatinous globule, if a microscope be near, it would be very 

 interesting to put the gummy masses between glasses in order to 

 examine them ; a good glass, indeed a pocket magnifying lens, will 

 be sufficient to show the beautiful srueture of the embryo shell, 

 and suggest many useful subjects for study. Whilst speaking of 

 the production of young snails, it will be well now to leave the 

 consideration of popular mistakes and mention one or two remark- 

 able facts not generally known. Some of them are Monoecious, 

 that is to say, some snails are both male and female in one body ; 

 others again are Diaecious, as would be expected ; that is, there are 

 males properly so called, and there are females properly so called. 

 A singular thing is said to occur in some water snails, they are 

 born males and become females. It will be interesting also to 

 state that some shells are oviparous ; that is, they lay eggs which 

 eventually become of the same species as themselves, some even 

 nurse them as a hen when sitting, whilst others are viviparous ; 

 that is, they give birth to their young in a living state. It may 

 also be said, that as in Botany certain plants receive their names 

 from odours they discharge, so there are certain snails which obtain 

 their names from smells emitted ; as for instance Zonites alliarins f 

 the Garlic Snail. It may be well to call attention to the beauty of 

 a cabinet of Land and Fresh-water Shells, the variety of shapes 

 assumed, the brilliancy of color as well as transparency, the gradual 

 process of development, and the minuteness of some species, all 

 combine to render them extremely pretty. And if from ordinary 

 observation as the shells lie empty, a microscope be used in the 

 examination, so as to view the dissected parts of the creatures, 

 (particularly with a good polariscope when the object will bear it), 

 wonders upon wonders are revealed, none being more beautiful 

 than the teeth : our largest slug, incredible as it may seem, has 

 no less than 28,800 teeth, one row of teeth numbering 180, whilst 

 the transverse row has 160, which quantities multiplied together 



