ON MICROSCOPIC DISCOVERY. 



621 



the attention of the microscopic observer to 

 " the numerous muscles for moving the body, 

 and its elegant branched arms, the disposi- 

 tion of those for producing a revolution of its 

 compound eye, the position of those for rais- 

 ing and depressing the respiratory organs, and 

 others for contracting and dilating the pulsa- 

 tory organ. The curious form of its shell, 

 and the various shapes of the reticulations on 

 different parts of its surface, the articulations 

 of its arms the singular construction of its 

 digestive organs the circulation of its blood, 

 and the delicate fringes appended to its 

 branchiae, afford ample materials for observa- 

 tion." A very faithful illustration of the 

 Monoculus quadricornis will be found in a 

 future page, in connection with the Vorticdla 

 digitalis, which frequently attaches itself to the 

 body of this insect. 



The Lepisma forms a genus in that order of 

 the insect class named aptera ; and includes 

 several varieties or species. The small book- 

 worm, as it is popularly called, ranks under 

 this genus : it is one of the most pleasing and 

 interesting microscopic objects known, whether 

 it be viewed in detail or observed entire. No 

 one seems to have examined this little crea- 

 ture with more attention than Hooke, whose 

 description is so popular and curious that we 

 offer it as the best account which can be given 

 of the inse-ct. "It is," says he, " a small, 

 white, silver-shining worm, which I found 

 much conversant among books and papers, and 

 is supposed to be that which corrodes and eats 

 holes through the leaves and covers ; it ap- 

 pears to the naked eye a small, glittering, 

 pearl-coloured moth, which upon the removing 

 of books and papers in the summer, is often 

 observed very nimbly to scud, and pack away 

 to some larking cranny, where it may the 

 better protect itself from any appearing dan- 

 gers. Its head appears big and blunt, and 

 its body tapers from it towards the tail, smaller 

 and smaller, being shaped almost like a car- 

 rot. This the microscopical appearance will 

 more plainly manifest, which exhibits a coni- 

 cal body, divided into fourteen several par- 

 titions, being the appearance of so many 

 several shells or shields that cover the whole 

 body ; every one of these shells is again covered 

 or tiled over with a multitude of thin trans- 

 parent scales, which, from the multiplicity 

 of their reflecting surface, make the whole 

 animal appear of a perfect pearl colour. This, 

 by the way, offers a reason for the appearances 

 presented by these scales, as also by mother- 

 of-pearl, and a multitude of other shelly sea- 

 substances ; for they each of them consisting 

 of an infinite number of very thin shells or 

 laminated orbiculations, cause such multitudes 

 of reflections, that the composition of them, 

 together with the reflection of others that are 



so thin as to afford colours, gives a very pleas- 

 ant reflection of the light The small blunt 

 head of the book-worm was furnished on 

 either side of it with a cluster of eyes, each of 

 which seemed to contain but a very few, in 

 comparison of what I had observed the clusters 

 of other insects to abound with ; each of these 

 clusters was beset with a row of small bristles, 

 much like the cilia, or hairs, on the eyelids, 

 and perhaps they served for the same purpose. 

 It had two long horns before, which were 

 straight, and tapering towards the top, curiously 

 ringed or knobbed, and bristled much like the 

 marsh weed, called horse tail, or cat's-tail, 

 having at each knot a fringed girdle of 

 smaller hairs, and several larger bristles, here 

 and there dispersed among them ; besides 

 these, it had two shorter horns or feelers, 

 which were knotted and fringed just as the 

 former, but wanted bristles, and were blunt 

 at the ends ; the hinder part of the creature 

 was terminated with three tails, in every par- 

 ticular resembling the two longer horns that 

 grew out of the head : the legs of it were 

 scaled and haired much like the rest." The 

 singular scales of this small insect have already 

 been illustrated and described. 



The lobster insect, represented in theannexed 

 cut, is figured and described by Adams in 



his Essays on the microscope. This insect 

 approximates in form and character to the 

 phalangium cancroides of Linnaeus ; it presents, 

 however, many remarkable points of diilerence, 

 and forms a microscopic object of great variety 

 and interest. We take Adams' description 

 as the best we can offer, " This extraordin- 

 ary little creature was found by my ingenious 





