OF MICROSCOPIC OBJECTS. 49 



On the surface of the leaves, hairs and scales of various and 

 very beautiful forms are found, most of which display their beau- 

 ties best when removed from the leaf, and used with the polarizer. 

 These will be noticed in another place ; but a portion of the leaf 

 should always be prepared in its natural form, to show the arrange- 

 ment of the hair or scales upon it ; which must almost invariably 

 be mounted dry when used for this purpose. Many of them 

 require very delicate handling. The epidermis, or, as it is by some 

 termed, the cuticle, is the outer skin which lies upon the surface 

 of the leaves and other parts of most plants. This is composed 

 of cells closely connected, often bearing the appearance of a rude 

 network. In many plants, by scraping up the surface of the leaf, 

 a thin coating is detached, which may be torn off by taking hold 

 of it with the forceps. The piece may then be washed and floated 

 upon a glass slide, where, on drying, it will be firmly fixed, and 

 may usually be mounted dry. Amongst the most beautiful and 

 easily prepared of these may be mentioned the petal of the gera- 

 nium, the cells of which are well defined and amongst the most 

 interesting. 



Closely connected with the leaves are the ANTHERS and POLLEN, 

 of which a great number are beautiful and interesting subjects for 

 the microscopist. 



The mallow tribe will furnish some exquisite objects, bearing 

 the appearance of masses of costly jewels. These are usually 

 dried with pressure, but the natural form may be more accurately 

 preserved by allowing them to dry as they are taken from the 

 flower, with no interference except thoroughly protecting them 

 from all dust. Sometimes the anther is divided, so that the cell 

 required to receive them may be of as little depth as possible. 

 The common mallow is a beautiful object, but I think the lavatera 

 is a better, as it shows the pollen chambers well, when dried un- 

 pressed. The pollen is often set alone, and is well worth the 

 trouble, as it then admits of more close examination. Often it is 

 convenient to have the anther and pollen as seen in nature on one 

 slide, and the pollen alone upon another. The former should be 

 taken from the flowers before their full development is attained, 

 as if overgrown they lose much of their beauty. Some pollens 

 are naturally so dark that it is necessary to mount them in Canada 



