xxxiv GLOSSAKY OF TECHNICAL TEEMS 



POLLINIA, solid aggregations of pollen grains found in the flowers 



of orchids. 

 POLYDACTYLISM (Gr. TToXvbaKTvXos, many-toed), a condition in 



which more than the normal number of fingers or toes are 



present. 

 POLYMOEPHIC (Gr. 77oAt^iop<o9, multiform), occurring in many 



forms. 

 POLYPE (Gr. -noX.vTrov$, many footed), a name applied to Hydra 



and various other Coelenterate animals in allusion to the 



numerous tentacles. 

 POSTAXIAL (Lat. post, behind; axis), lying behind the axis of a 



limb. 

 PEEAXIAL (Lat. prce, in front ; axis), lying in front of the axis 



of a limb. 

 PRE -FORMATION, an old theory in accordance with which every 



egg contains a complete miniature of the organism into 



which it will develop. 



PREHENSION (Lat. prehendere, to seize), catching hold. 

 PRIMORDIA (Lat. primordium, origin), hypothetical particles of 



the germ plasm which are supposed to be responsible for 



the development of special inheritable characters. 

 PRIMORDIAL UTRICLE (Lat. primordium, origin ; utriculus, little 



bag), the protoplasmic lining of a typical vegetable cell, next 



to the cell wall. 

 PROBOSCIS (Gr. TT/JO/SOO-KIS, trunk, snout), a term somewhat loosely 



applied to any prehensile, suctorial or other organ which 



projects from the neighbourhood of the mouth. 

 PROCRYPTIC (Gr. -npo, on behalf of ; KpuTirds, hidden), a term applied 



to protective resemblance whereby concealment is effected. 

 PRONUCLEUS (Lat. pro, in place of >, nucleus, kernel), the reduced 



nucleus of a mature gamete before it unites with its mate 



to form the zygote nucleus. 

 PROTANDROUS (Gr. vp^-os, first ; avfip, man, male), a term applied 



to hermaphrodite organisms in which the male organs 



mature before the female. 

 PROTEIDS, PROTEINS (Gr. npwrtvs, the changeable one), a group of 



complex chemical compounds which form the chief con- 

 stituents of protoplasm. 

 PROTHALLUS (Lat. pro, in place of ; thallus, a green stalk), the 



sexual individual (gametophyte) in ferns, &c. 

 PROTOGYNOUS (Gr. -np&rov, first; yvvri, woman, female), a term 



