the saucer a few drops of water, and repeat this until the required consistence be obtained. 36. _Muscle._—Harden in chromic acid, and cut in paraffine. Transverse sections may be made to show the shape of the fibrils. Longitudinal sections will only be required in the case of injected tissues, when such sections will be found very elegant, showing, as they do, the elongated meshes of capillaries running between and around the muscular fasciculi. Mount in glycerine or balsam. To see the transverse striæ characteristic of voluntary muscle, a very good plan is to take a bit of pork (cooked or fresh), and by means of needles to teaze it out into the finest possible shreds. If these be examined in water or glycerine, the markings will be shown very perfectly. 37. _Orange-peel_, common object though it be, is not to be despised by the microscopist. Transverse sections must be prepared by the gum method (§ 35). These sections are not to be subjected to the action of alcohol (as this would destroy the colour), but after _drying_ between glass slides they must be soaked in turpentine and mounted in balsam. We shall then have a good view of the large globular glands whose office it is to secrete that essential oil upon which the odor of the orange depends. 38. _Ovary_ may be prepared in the same manner as liver (§ 34). Sections, which are to be cut in paraffine, may be stained with carmine, and mounted in glycerine or balsam. Apart from all scientific value, we know of no slide for the microscope which, even as a mere object of show, surpasses in beauty a well-prepared section of _injected_ ovary, showing the wondrous Graafian vesicles, surrounded by their meandering capillaries. 39. _Porcupine Quill._—Soften in hot water, cut in paraffine, and mount in balsam. Much (in our opinion _too_ much) lauded as an object for the polariscope. 40. _Potato._—From the large amount of water which it contains thin sections cannot be cut from the potato in its natural state. It must, therefore, be partially desiccated, either by immersion in methylated spirit for a few days or by exposure to the air. Sections may then readily be obtained by imbedding and cutting in paraffine. Such sections mounted in balsam are very beautiful, the starch being seen _in sitú_, whilst if polarized light be employed each granule gives out its characteristic black cross. 41. _Rush_ is to be prepared and cut as orange-peel (§ 37). Transverse sections of this “weed” furnish slides of the most exquisite beauty.