Part III 



ECOLOGY 



PAKASITIC AND CAENIVOEOUS PLANTS 



144. Field study of parasites. 



A. Study out of doors any parasitic seed plants that you can find. 

 In most parts of the country the dodders are of much more fre- 

 quent occurrence than any other parasites among the higher plants. 

 Frequently several species of dodder can be found. 



Note and collect the host plants on which the parasite grows and 

 observe the mode of attachment between parasite and host. Find out 

 whether the host is at all injured by the parasite. 



B. If possible transplant thriving specimens of the parasite upon new 

 kinds of host and see whether they will grow there. Collect seeds of 

 any parasitic plants found, germinate the seeds, and make studies of 

 the behavior of their seedlings. Are the seedlings green at first ? 



Reference. Kerner-Oliver, 2. 



1 45 . Field study of camivorous plants. 



A. Examine any carnivorous plant which you can find growing sponta- 

 neously (various species of Drosera and Sarracenia are the kinds most 

 widely distributed). Make notes on the total number of insects cap- 

 tured by a single plant and by a single leaf. 



B. In the case of Drosera study and draw various leaves, some expanded 

 and some closed over insects. 



C. Put into 50 per cent alcohol or 2-4 per cent formalin solution all the 

 insects obtained from any one kind of carnivorous plant and bring 

 them to the laboratory for determination of the groups. 



146. Laboratory study of carnivorous plants. 



A. Put living flies in the pitchers of Sarracenia containing their usual 

 amount of liquid, and note whether any of the flies escape, or what 

 finally becomes of them. 



B, Feed leaves of Drosera with bits of raw meat, particles of cheese, very 

 small insects, bits of sand, or broken glass. Place the objects very 



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