Glossary 341 



Par-a-me'-ci-um. A ciliated protozoan. 



Par-the-no-gen'-e-sis. Development of an egg without previous fertili- 

 zation. 



Particulate Inheritance. Gallon's term for that kind of inheritance in 

 which certain characters are derived from one parent and others from 

 the other parent, i.e., Mendelian Inheritance. 



Pa-thol'o-gy. The science which deals with disease. 



Phe'-no-type. The developed type in which some of the hereditary pos- 

 sibilities are realized while others remain undeveloped. "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 kingdom. 



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 num- 

 ber of digits on hands or feet. 



Pol-y-hy'-brid. The offspring of parents differing in more than three 

 characters. 



Pre-for-ma'-tion. The doGtrine that the fully formed organisms exists 

 in the germ, and that development is merely its unfolding. 



Pre-in-duc'-tion. A modification of the second filial generation caused 

 by the action of environment on the germ cells of the parental genera- 

 tion. (Woltereck.) 



Pre-in-her'-it-ance. The transmission of characters developed in a pre- 

 vious generation. 



Pre-po'-tency. The preponderance of one parent over the other in the 

 transmission of hereditary characters. 



Pri'-mates. The highest order of mammals, including monkeys, apes, and 

 man. 



Primitive Sex Cells. The earliest recognizable progenitors of the s< x 

 cells in development. 



Pro'-te-in. Complex organic substances containing nitrogen, e.g. white 

 of egg. 



Pro-te'-nor. A genus of the true bugs. 



Pro'-to-plasm. The living material of an organism. 



