ESSENTIALS OF COLLEGE 

 BOTANY 



CHAPTER I 



PROTOPLASM AND PLANT CELLS 

 CYTOLOGY 



1. Protoplasm. Plants, like animals, possess as their 

 living portion a soft, viscid, more or less granular sub- 

 stance called protoplasm. This living matter makes up, 

 ordinarily, only a rather small proportion of the total 

 substance of the larger plants, being present in larger 

 proportion in the smaller, simpler organisms. In the 

 rapidly growing parts of plants it is far more abundant 

 than in the fully developed organs. 



2. Protoplasm, when studied under high magnifica- 

 tions with the use of certain stains, is found not to be a 

 homogeneous substance but to occur in various forms 

 as follows: (1) Cytoplasm. This is the bulk of the pro- 

 toplasm and that which probably performs most of its 

 ordinary functions. It is less dense than the other forms, 

 being often of about the consistency of the white of an 

 egg. It appears to consist of a clear, more or less liquid 

 portion in which are imbedded innumerable granules of 

 all sizes, from those easily visible under moderately high 

 magnification to those barely visible at the highest possi- 

 ble magnification. (2) Nucleus. This is a somewhat 

 denser portion of the protoplasm, usually of definite 



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