ASEXUAL PROPAGATION OF PLANTS ON OWN ROOTS 65 



crocus are examples of plants producing corms. Usually 

 they propagate themselves by forming a new corm above the 

 old. They are propagated in the same manner as bulbs. 



99. Media for growth. Sand and sawdust have been 

 mentioned as suitable media for starting cuttings. On ac- 

 count of its ability to hold the proper amount of moisture, 

 fairly coarse sharp sand is most generally useful. Very 

 coarse sand does not hold sufficient moisture, while very fine 

 sand contains too much moisture and packs so closely as to 

 interfere with the supply of oxygen. Therefore, sand of 

 medium texture is best. In order to lessen the liability of 

 disease, there should be no organic matter present in the 

 cutting-bed. Sand from fresh water streams is good. Sand 

 from any sand-pit may be used with safety after it has been 

 exposed to the action of weather for a month or two. A con- 

 venient way to cleanse sand for the cutting-bed is to place 

 it in a water-tight container and wash it with a stream of 

 water from a hose until the run-off is clear. 



100. Temperature. The air above the cutting-bed should 

 be cool enough to discourage the growth of the tops of the 

 plants until roots form. Sufficient bottom heat should be 

 given to stimulate the growth of tissues. The bottom of the 

 cuttings should be kept from 5 to 15 degrees warmer than 

 the air above ground, especially in the propagating of plants 

 with soft tissue. 



101. Apparatus for growing cuttings. Various ways of 

 regulating temperature and moisture conditions have been 

 devised. A few kinds of cuttings, such as those from olean- 

 ders, will produce roots if the cutting is kept in a moderately 

 warm room and the base end is placed in a bottle of water. 

 Sometimes a small unglazed flower-pot is placed inside of a 

 large one and the spaces between are filled with moist sand 

 in which the cuttings are planted. The hole in the bottom of 

 the inner unglazed pot is plugged and the inner pot is filled 

 with water which seeps through gradually, thus keeping the 



