510 GLOSSARY 



O-VI-PAR'-I-TY. Young brought forth as eggs, i.e., in an early 

 stage of development. 



O'-VULES. The female sex cells of flowering plants with the 

 immediately surrounding parts. 



O'-VUM. The female sex cell. 



OX-Y-CHRO'-MA-TIN. That portion of the chromatin which 

 does not form chromosomes. 



PAN-GEN'-E-SIS. The hypothesis proposed by Darwin that every 

 cell of the body gives off minute germs, "gemmules," which 

 then collect in the sex cells. 



PAR-A-ME'-CI-UM. A ciliated protozoan. 



PAR-THE-NO-GEN'-E-SIS. Development of an egg without pre- 

 vious fertilization. 



PARTICULATE INHERITANCE. Gallon's term for that kind of in- 

 heritance in which certain characters are derived from one 

 parent and others from the other parent, i.e. Mende- 

 lian Inheritance. 



PA-THOL'-O-GY. The science which deals with disease. 



PHE'-NO-TYPE. The developed type in which some of the her- 

 editary possibilities are realized 1 while others remain un- 

 developed. "Developed, measurable realities" (Johannsen). 



PHY-LOG'-E-NY. Evolution of a race or species. 



PHYL-LOX'-E-RA. A genus of plant lice. 



PHY'-LUM. One of the chief sub-divisions of the animal king- 

 dom. 



PHYS-I-OL'-O-GY. The science which deals with function. 



PLAS'-TO-SOMES. Threads or granules in the cytoplasm which 

 are colored by certain dyes. 



POLAR BODIES. Two minute cells which are separated from 

 the egg in its two maturations divisions. 



PO-LAR'-I-TY. The condition where two poles of a body differ; 

 in eggs the two poles are the animal (formative) and the 

 vegetative (nutritive) . 



POL'-LEN. The male sex cells of flowering plants. 



POL-Y-DAC'-TYL-ISM. The condition of having more than the 

 normal number of digits on hands or feet. 



POL-Y-HY'-BRID. The offspring of parents differing in more 

 than three characters. 



