THE POCKET LENS, THE DISSECTING MICROSCOPE, AND SOME SIMPLE APPLIANCES The object of this little book is to show how much may be seen with an ordinary pocket lens, and with a simple microscope; and, as far as possible, to dispel the idea, far too common, especially among beginners, that no real work can be done unless one has a compound microscope, with a large battery of lenses and an array of ‘accessories.’ It would be easy to multiply quotations, from high authorities, in support of the proposition implied in the foregoing paragraph. Two only must suffice. In a recent review of a very good book dealing with Butterflies and Moths (_Natural Science_, vol. vi. p. 293), the following passage occurs: ‘The only suggestion we should like to make is that a compound microscope is unnecessary for any of the details that the author mentions. A first-rate platyscopic hand lens is much more convenient and the young naturalist should train himself thoroughly in the use of it. There is no more common error than the undue use of the higher powers of a microscope. Except for the intimate details of histology, a low power or a hand lens is much more easy to use, and its employment gives a much better idea of the structure.’ The next quotation is of greater interest, as it gives some insight into the way in which Darwin carried on his investigations. In the _Life and Letters of Charles Darwin_ (vol. i. pp. 145, 146) we are told: ‘His natural tendency was to use simple methods and few instruments. The use of the compound microscope has much increased since his youth, and this at the expense of the simple one. It strikes us nowadays as extraordinary that he should have had no compound microscope when he went his Beagle voyage; but in this he followed the advice of Robert Brown, who was an authority in such matters. He always had a great liking for the simple microscope, and maintained that nowadays it was too much neglected, and that one ought always to see as much as possible with the simple before taking to the compound microscope. In one of his letters he speaks on this point, and remarks that he always suspects the work of a man who never uses the simple microscope.’