142 Gardening 



solid; then the pollen may be scattered over it. Keep in moist 

 air as directed above. The pollen of corn, which does not ger- 

 minate on sugar and water, germinates readily on the agar-sugar- 

 water mixture. 



If the pollen is in good condition, it often germinates in an 

 hour; and the tubes may grow until they are ten times as long 

 as the pollen grains are wide. Examine the germinating pollen 

 under a compound microscope and note the delicate, slender, 

 tube-like plant with its almost colorless granular living material 

 that grows from the pollen grain. 



4. To observe the location of the ovules. Split a few pistils of peas, 

 beans, squashes, or cucumbers after the corolla has withered and 

 fallen and the fruits have begun to develop. Find the ovules, 

 that are developing into seeds. 



5. To learn varieties of garden vegetables. Observe closely the 

 individual plants of the various garden crops and learn to judge 

 those that are best and truest to type. In this way learn to 

 distinguish the varieties of each crop. 



6. To learn to recognize the seeds of garden vegetables. Make a 

 collection of the seeds of garden vegetables, keeping each kind 

 separate in wide-mouth bottles of suitable sizes. Square, screw- 

 top glass jars of one-half-ounce and one-ounce sizes (to be obtained 

 at most drug stores) are excellent for such a collection. Note the 

 characteristics of each kind and how it differs from the others. 



Also collect, study, and learn to recognize the seeds of common 

 weeds. 



7. To test the viability of seeds. Make the two tests for viabil- 

 ity mentioned in this chapter, using as many different kinds of 

 seeds as possible. Record the results in your garden notebook. 



8. To demonstrate that pollination is necessary for fruit and seed 

 production. Select at least four corn plants having ears from 

 which the pistils ("silks ") are not quite ready to protrude. Invert 

 over each ear a paper bag (two-pound size), and fit the open end 

 around the ear at a point slightly above the middle ; then tie the 

 bag in place with ordinary twine. The end of the ear is thus 

 completely inclosed within the bag, and no pollen can reach the 

 pistils. 



Leave the bags undisturbed on half the number of ears until 

 there is no chance that pollination can occur (this will be about 

 10 days from the date of bagging). Examine the other ears from 



