H03 



1 



UNIVERSITY HIGf! 



lib: 



PROTOPLASM IS S]^ECI4i^I7.ED r. michiga.n 



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* 



special set of protective structures called trichocysts. Each one 

 of these structures consists of a pocket fitted with a long strand of 

 cytoplasm which is thrown out when danger is near. This strand 

 secretes a poisonous substance. 



I/oCoction. 

 of 





If a small drop of fountain pen ink is put on 

 a Paramecium, the animal throws out long 

 protoplasmic structures, trichocysts. These 

 threads usually secrete a substance that stuns 

 an enemy or the prey. 



The whole mechanism acts as 

 a protection. A worm, much 

 larger than a Paramecium, as 

 it thrashes about, might injure 

 the Paramecium. To protect 

 itself, the Paramecium dis- 

 charges trichocysts which will 

 pierce or poison the enemy so 

 that it will become inactive. 



Protoplasm is specialized. 

 The specialization of protoplasm 

 in Paramecium is a step toward 

 the specialized organs for defi- 

 nite functions found in higher 

 animals. The protoplasm of 

 the amoeba shows very little differentiation. Pseudopodia may be 

 thrown out from the body at any place. Food may be taken in and 

 w^ater given off from any part of the body. The only specialized 

 protoplasm of the amoeba seems to be the nucleus and the plasma 

 membrane around the contractile vacuole. In the Paramecium 

 there are definite parts of cytoplasm specialized to form cilia. 

 These are constant structures used for locomotion and for propel- 

 ling food into the mouth. There is a definite part of the cytoplasm 

 forming the groove, mouth, and gullet. Food is taken in through 

 these structures. The two nuclei, the contractile vacuoles, cell 

 membrane, and anal canal are all fitted or adapted to the functions 

 they have to perform. The Paramecium is one of the simplest 

 organisms to show definite adaptations to function. Physiological 

 division of labor is accomplished by specialized protoplasm. 



