MICROSCOPE. 



665 



we refuse reason priority of place over mere mat- 

 ter, what becomes of the reasoning of these men ? 

 There's the rub. 



Fig. 10. Scale of the Red Undenting Butterfly. 

 This minute atom exhibits a very beautiful for- 

 mation, under a deep power of the microscope. 

 The longitudinal striae are resolved by a good pene- 

 trating power into what may not unaptly be termed ; 

 strings of beads. It is asserted that this appear- 1 

 ance in the object under review, and in others of 

 this class, is produced by the interlocking of the 

 serrated edges of the fibres composing the scale. 

 We have not ourselves observed anything confirm- 

 ing this opinion, and therefore content ourselves 

 with exhibiting the object as we saw it, under an 

 amplifying power of 90,000 on the surface. To 

 avoid repetition, we may observe that the power 

 just mentioned applies to the succeeding objects so 

 far as No. 20, inclusive. 



Figs. 11, 12, 13. Scales of the Brassica Butter- 

 fly. These are three varieties of scales from the 

 wings of the Brassica. Fig. 11, resembles in the 

 striae the scale of the red under-wing ; but there 

 is a marked difference in the contour of the two 

 objects. Fig. 12 exhibits a very delicate and 

 transparent scale, with exceedingly fine longitudi- 

 nal striae. We consider this object a very severe 

 test of defining' power, for many instruments that 

 will show the markings of the podura with much 

 distinctness, fail to develope it ; it requires a very 

 skilful management of the light, a most accurate 

 adjustment, and a faultless doublet, to exhibit it 

 satisfactorily. Fig. 13 is termed the Brassica 

 curiosa ; it is no less remarkable for its exterior 

 form, than for the singular disposition of the striae 

 on its surface. 



Fig. 14. Scale of the Menelaus Butterfly. This 

 object consists of a fine tissue overlaid with strong 

 and well defined lines. The latter are frequently 

 detached from the tissue, or membranous part, as 

 shown in our specimen ; and consequently there 

 can be no illusion or misconception regarding these 

 lines, which are evidently fine fibrous cords in re- 

 lief, upon the surface of the scale. 



Fig. 15. Scale of Papilio. This is a very singu- 

 lar scale observed amongst a miscellaneous group. 

 The longitudinal striae are strongly defined, and 

 the cross markings arise from a contraction, or 

 shrivelling up, of the membraneous part between 

 nach two of the striae. 



Fig. 16. Scale of the Azure Blue Butterfly 



The light coloured and most diaphanous scales of 

 this species form beautiful test objects for the mi- 

 croscope. The striae are delicate, but are easily de- 

 fined by a good doublet. 



Fig. 17. Scale of the Podura The podura, or 

 skiptail, a small insect found in wine cellars, is 

 most readily obtained by examining a small quantity 

 of the dust in which the wine is packed.under a mo- 

 derate power of the microscope. This little creature 

 is covered with exceedingly minute scales, which 

 have been adopted as microscopic test objects of 

 the very first class. A most accurate adjustment, 

 excellent defining power, and a judicious manage- 

 ment of the light, are requisite to develope this 

 delicate structure. The longitudinal striae are 

 brought out with most difficulty, though some obser- 

 vers contend that the waved lines, frequently ob- 

 servable on the larger scales, are a more severe test. 



Fig. 18. Scale of the Lepisma. The lepisma is 

 a small fish shaped insect, of pearly whiteness, 

 covered with a number of delicate scales, one of 



which is shown in our engraving. The striae on 

 this object are easily developed, and they have the 

 same character with those on the scale of the 

 menelaus, as is evidenced by the partial detach- 

 ment of the lines from the membraneous tissue. 

 There is a variety in these scales : the one we have 

 selected, and on which the markings are more deli- 

 cate, is nearly oval shaped ; but there are others 

 much resembling a shell, and having the upper edge 

 scalloped very regularly. Diagonal markings are 

 perceptible on most of the latter species ; these 

 appear to be produced by spiny projections from the 

 longitudinal lines. 



Fig. 19. Scale of the Diamond Beetle. Every 

 possessor of a microscope will be familiar with the 

 wing-case of the diamond beetle, one of the most 

 beautiful opaque objects on which the eye can rest. 

 We may compare the appearance it presents to that 

 of the ancient Jewish breast-plate ; a number of 

 small cavities, regularly disposed over the surface, 

 are filled with a vast number of small scales, which 

 reflect every variety of hue, and exhibit a lustre 

 and magnificence that dims the splendour of the 

 most richly arranged jewellery. Our figure shows 

 one of these minute scales, with its semi-opaque 

 spots and striated markings. 



Fig. 20. The scale of a Moth. This object is 

 very opaque, compared with preceding ones, and it 

 is consequently difficult to trace its structure with 

 much precision. The contour, it will be seen at 

 once, is that of a leaf; and the vegetable analogy 

 would seem to extend much farther. This scale 

 appears to consist of a fibrous frame-work, resem- 

 bling very much the skeleton of a leaf; and the 

 interstices are filled up with a mossy substance, 

 whilst the prismatic reflections, and other charac- 

 teristics of the surface would indicate that smaller 

 scales are scattered over it. 



Fig. 21. Disposition of the Scales This is a 

 small diagram, intended to convey an idea of the 

 disposition of the scales on the membrane of a 

 butterfly's wing. The double lines of points mark 

 the places where the scales are inserted ; and it 

 will be noticed that there are two sets of them, 

 one considerably shorter than the other. The 

 longer scales are inserted in the upper line over- 

 lapping each other, and the shorter, in the line be- 

 neath ; by which means these extend to the middle 

 of the long scales, and have their extremities 

 covered by the next line. 



Figs. 22, 23, 25. Wings of Insects. To have 

 given with full effect the remarkable details in the 

 wings of insects, we must necessarily have shown 

 them on a very large scale, and by consequence 

 have restricted our illustrations to a very small 

 number, which would not have fulfilled the design 

 in view. The reader will therefore consider these 

 figures as little more than an indication of the won- 

 drous beauty, delicacy, and variety discoverable in 

 this class of objects. Indeed, the amplifying power 

 under which they are shown, is scarcely 60 on the 

 surface. Fig. 22, exhibits the wing of a gnat with 

 the beautiful fringe on its circumference, the spin- 

 ated fibres, and the delicately marked membrane. 

 Fig. 23, shows the general character of the wing 

 of the ichneumon fly. Fig. 25, is the beautiful 

 shell-shaped wing of the earwig. These three 

 objects come up in a very pleasing and interesting 

 manner under a compound power, sufficiently mo- 

 derate to keep the whole figure in the field. 



Fig. 24. Foot of a Dytiscus. This figure ex- 

 hibits, under a very low power, the foot of that most 



