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FOUNDATIONS OF BIOLOGY 



shifting of individuality from the cells to the colony as a 

 whole. This specialization is exhibited chiefly with regard 

 to reproduction and reaches its highest expression among 

 colonial PROTISTA (Protozoa and Protophyta) in VOLVOX, 

 where among ten thousand or so cells, perhaps a score are 

 specialized for reproduction and the rest are vegetative. 

 Usually each of the reproductive cells (germ cells) divides 



A. Paramecium. 



B. Volvox. 



CELL DIVISION CELL DIVISION CELL DIVISION PERMANENT CELL DIVISION 

 (Colony for- (Asexual Re- (Gamete for- CJN.IUGA- (Colony forma- 



mation) production) mation) TION tion) 



Zygote (z) de- Germ cells (g.c.) Certain germ (Fertilization) Zygote develops 

 velops into a give rise to new cells produce One sperm into a colony, 

 colony. colonies. eggs (e) ; others fuses with one etc. 



sperm, (sp.) egg, forming 

 a zygote (z). 



