26 Objects for the Microscope. 



a flower first opens the anthers are closed all round ; but as 

 soon as the air and the light have perfected the pistil and 

 caused it to secrete a kind of gum, or viscid liquid, on the 

 surface of its stigma, intended to hold fast the pollen-grain, 

 the anthers open and the golden dust appears, falling on 

 the ready channel, which conveys it to the ovary beneath. 

 The pollen-grain itself is not a simple cell, as we might at 

 first suppose : minute as it is there are many cells therein, 

 and a subtle fluid, called fovilla, which is in reality the life- 

 giving principle to the ovule. When a pollen-grain falls 

 upon the stigma it presently opens one of its pores, and 

 sends forth a tube more or less long, which descends 

 through the tissues of the style, enters the ovary, reaches 

 a tiny ovule, and pours it into the fovilla, which fovilla 

 forms the embryo or future plant that is preserved and 

 nourished in the seed. 



Take a little pollen from a Cucumber plant or Passion- 

 flower, and when it is fairly under the microscope, covered 

 with thin glass, let a drop of water run in. The moisture 

 is absorbed by the pollen-grain, and it throws out a tube 

 and discharges the fovilla. It goes off like a little cannon, 

 a cloud of fovilla waving on the slide. 



The quantity of pollen in a flower is astonishing. A 

 flower of the Peony, for instance, has about 174 stamina, 

 each containing 21,000 granules, total, 3,654,000 pollen- 

 grains. A single Dandelion has 243,000 pollen-grains. 

 The contents of one anther are quite sufficient for the fruc- 

 tification of all the ovules ; but the superabundance is not 

 wasted, for thousands of insects live on the golden store, 

 and the busy bee fills her baskets hourly with these pretty 

 cakes for her nurslings. 



POLLEN-TUBES. 



To see the actual pollen-tubes in their passage down the 

 style is a more difficult matter ; nevertheless, with care and 

 a good glass it may be managed. Put on the J-inch and 

 choose a flower with a very stout style, a Cistus or this 

 Chickweed ; the flower must have just faded, then you may 

 be sure .the ovules are fructified. With a sharp razor make 



