372 GLOSSARY 



Spore: A single cell, incapable of syngamy, but capable 



of giving rise to a new individual without the sexual 



process. 

 Symbiosis: The obligatory association of two organisms of 



different species for mutual benefit. 

 Synapsis: Union in pairs of corresponding (homologous) 



chromosomes of opposite parental origin as a preliminary 



to their separation in meiosis. 

 Systematist: An expert in classification (systematics), i.e., 



a taxonomist. 



Taxonomy: The science of classification. 



Tertiary Period: A geological time-division corresponding 

 to the rock-system that comprises the greater part of the 

 Cenozoic group. It is made up of four series, namely, 

 the Eocene, Oligocene, Miocene, and Pliocene. Its close 

 marks the beginning of the Glacial or Pleistocene epoch. 



Tissue: A layer of uniform cells specialized for the same 

 function. 



Tissue Cell: One of the somatic cells of which a tissue is 

 composed. 



Troglodytic: Resembling the chimpanzee and the gorilla. 



Woods Hole: The seat of the Marine Biological Laboratory. 

 It is a watering-place on the New England coast opposite 

 Martha's Vineyard. 



Zygote: The synthetic cell formed by the union of two 

 gametes and giving rise by division either to a new multi- 

 cellular organism, or to a rejuvenated cycle of unicellular 

 forms. 



