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quantities of pollen. It insures that the chance currents of wind will 

 carry the pollen to the young cones. 



The microscope will show the interesting form of the pollen grains, 

 and how, by a sort of minute wings, they are better carried by the wind. 

 The yellow dust on the sidewalks or on little pools after a wind-storm 

 at this time of the year is pine pollen. The microscope will determine 



this. 



Having seen how th.; pollen-producing flowers (staminate) and the 

 cones (pistilate) of the pines are arranged, the same organs in 

 the redwoods, cypress, firs, cedars, and whatever cone-bearing plants 

 which may be in the city may be observed. The plants are essentially 

 the same, although the size and shape of the cones differ greatly. This, 

 of course, gives an excellent opportunity for an exercise in making com- 

 parisons and drawing conclusions. 



Pond Life. 



(With microscope.) 



A number of papers will appear from time to time under this head, 

 concerning various forms of life found in ponds and ditches; these forms 

 may be transferred to the aquaria of the schoolroom for observation. 

 There is no end to the list of these forms, both animal and plant. Some 

 are only seen to an advantage with the microscope, others are large 

 enough to be seen with the naked eye. The eggs of frogs, toads, sala- 

 manders and mosquitoes belong to this number. 



THE GREEN SCUM OF PONDS. 



This consists chiefly of a number of beautiful microscopic plants. 

 The mass of it gathered one day may be made up of one group; on 

 another day it may consist of an entirely diflFerent group. Consequently 

 it would be impossible to anticipate and describe what might appear. 

 It is a good lesson if it goes no farther than having pupils find out that 

 the green scums consist ot definite forms of plants, and having them 

 associate with these forms, many animals. 



Have some one bring in a portion of such scum. Place it in a vessel 

 of water, giving it plenty of room to spread out well. Take up a very 

 small portion (too great a portion will give confusion only) and mount 

 it in water on the glass slip with a cover glass. Allow the children to 

 see it well and make out some of the forms. There will be great interest 

 on the part of the children, but at first very wrong conceptions of what 

 is seen. 



One form of plant is very likely to occur. It consists of a single, long 

 unbranched thread. Within it are green spiral bands of chlorophyll. 

 The partitions across the plant are the ends of plant cells. The plant 

 consists of a single row of cells. Those who are acquainted with Botany 

 will recognize the plant as spirogyra, of which there are at least forty 



