260 THE MICROSCOPE AND ITS LESSONS. 



fairly represented, and a dissolving view may be imme- 

 diately obtained by revolving the milled head either of 

 the prism or analyzer. 



You remember how in our botanical studies we were 

 surprised at the wonders displayed in our skeleton leaves. 

 Without polarized light their perfect beauty would all lie 

 concealed ; and as for the Deutzia leaf, why, when we get 

 a dark-blue background, and the starry cuticle in bright 

 gold, we have seen that it resembles a glorious patch of 

 the heavens laid down upon the microscope, and we really 

 seem to be surveying that land which is far off. Then, 

 because it is always wise in the study of nature to compare 

 one tiling with another, let us take the so-called palate of 

 a limpet. This, we shall examine, measures very nearly 

 two inches in length ; it is commonly called the tongue, 

 and consists of a vast number of teeth, which are used for 

 cutting through the shell of an oyster when the limpet 

 goes after its dinner. You have seen good-sized pin- 

 holes, I dare say, on oyster-shells. They have been sawn 

 by such parasites as the limpet, who knows just where to 

 reach that strong but solitary muscle with which the 

 oyster closes the door of its dwelling on the approach of 

 an intruder. Perhaps you may have attempted opening 

 the shell with your fingers, and, if so, you will know what 

 power is in that muscle ; but the limpet, with its saw-like 

 tongue, cuts through the shell, and very often the muscle 

 as well, when the poor bivalve is at its mercy. 



It is strikingly interesting to reflect upon the remark- 

 able age in which we live. In our daily papers, amidst 

 all the strife of politics and the bustle of life, yet what 

 room do some find for contemplating the wonders of 

 nature in little things ! While writing upon the palate 

 of the limpet, I observe some very interesting articles 

 in the Standard newspaper, from which I learn the true 



