Plasmodium 



The mass of cytoplasm containing many nuclei that is 

 enclosed by a single plasma membrane, occurring in Slime 

 molds (q. v.). cf. Syncytium, Coenocyte. 



Plasmolysis 



The shrinking of the Cytoplasm from the cell wall, 

 caused by osmosis of water out of the cell. 



Plasticity 



(1) The capacity of an organism to adapt itself to various 

 environmental conditions. (2) The capacity of a soil to be 

 changed in shape under applied stress and to retain the im- 

 pressed shape after removal of the stress. 



Pkutid 



A protoplasmic body in the Cytoplasm in cells of plants, 

 e. g., Chloroplast, Leucoplast, Chromoplast. 



Maya 



Undrained, flat, barren basins that are usually dry and 

 often saline, in arid and semiarid regions. 



Pleistocene 



The geological epoch preceding the Recent in the Quat- 

 ernary period of the Cenozoic era, which began about one 

 million years ago and lasted for about one million years. 



Pleomorphic 



Refers to an organism that has two or more forms in its 

 life cycle, cf. Polymorphism. 



Pleuston 



A one-layered community of plants that float on or 

 within bodies of water, cf. Plankton. 



Pliocene 



The latest geological epoch in the Tertiary period of the 



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