GLOSSARY ^61 



HETEROAGGLUTININ - agglutinin (fertillzin) of eggs which acta on sperm of different species, substance 



extractable from egg water which causes irreversible agglutination of foreign sperm. 

 HETERAUXESIS - the relation of the growth rate of a part either to another part of or to the whole 



organism. May include comparison of organisms of different sizes and ages, but of the same grouD. 

 (See growth, heterogonic; isauxesia, bradyauxesls, tachyauxesis. ) 

 HETEBOCHBOMATIN - part of the chromatic structure which seems to be related to the formation of the 



nucleolus. Takes a violet stain after methyl green but is digested away by ribonuclease. Probably 

 represents both thymo- and ri bo-nucleic acids. 

 HETEBOCHBONY - alteration and reversal of the sequence of stages in ontogeny. 

 HETEBOGONY - constant differential growth ratios (Pezard, I9I8). 

 HETEBOGONY, NEGATIVE - when the growth coefficient is below unity. 



HETEBOGONY, POSITIVE - when the growth coefficient is above unity, the parts increasing in relative size. 

 HETEBOMOEPHOSIS - differential morphological differentiation under varying environmental conditions wherein 

 the major animal gradient la flattened; appearance of an embryonic organ inappropriate to its site; 

 regenerated part different from that which was lost. Bateson's homoeoals or Goethe's metamorphy. 

 HETEROPLASIA - development of a tissue from one of a different kind. 

 HETEBOPLEUBAL - transplant to the other of bilateral sides. 



HETEEOPLOIDY - any deviation from the normal diploid number of chromosomes (Winkler, 19l6)- 

 HETEBOPYCNOSIS - condensation of some (sex) chromosomes in gametogenesis. 

 HETEBOTOPIC - transplant to same side but different region from the original. 

 HETEBOTBOPHIC - acquiring nourishment from without the orgeinism. 

 HIBERNATE - to spend the cold (winter) period in a state of reduced activity (n., hibernation). Opposed 



to aestlvate, 

 HISTOGENESIS - the appearance, during embryonic development, of histological differentiation; the develop- 

 ment of tissue differentiation. 

 HISTOLYSIS - the destruction of tissues. 

 HISTOPELEOSIS - process by which a cell-line, already Irreversibly differentiated, proceeds to Its final 



histological specialization (Hoadley). 

 HISTOMEBE THEOBY - ontogenetic division of histological systems resulting in the synthesis of vi (higher) 



organ ( Heidenhain) . 

 HISTOTBOPHE - the nutritive substances supplied to the embryos of viviparous forms from sources other than 



the maternal blood stream (e.g., from uterine glands). 

 HOLOENTOBLASTIA - blastula almost entirely composed of endoderm used by Herbst for sea urchin larvae with 



nearly complete suppression of ectoderm by ll\.hlum salts. 

 HOLOMORPHOSIS - entire lost part replaced at once or later. 

 HOLTFBETER'S SOLUTION - now designated (by Holtfreter's request) Standard Solution. NaCl - 5-5 gr. , 



KCl - 0.05 gr., CaClg - 0.1 gr., NaHCO} - 0.2 gr., %0 - 1 liter. 

 HOMOIOTHEBMAL - refers to condition where the temperature of the body of the organism is under the con- 

 trol of an internal mechanism; the body temperature is regulated under any environmental conditions. 

 Opposed to poikllothermal. Syn., warm blooded (animals). 

 HOMOIOTBANSPLAHTATION - transplantation between different but related individuals. 

 HOMOLOGOUS - organs having the same embryonic development and/or evolutionary origin, but not necessarily 



the same function. 

 HOMOMOBPHOSIS - new part like the part removed ( Drlesoh) . 

 HOMOPLEURAL - transplant to some same as that from which It was renoved. 

 HOBIZOKTAL - an unsatisfactory term sometimes used synonymously with frontal, longitudinal, and even 



sagittal plane or section. Actually means across the lines of gravitational force. 

 HOBMONE - a secretion of a ductless gland which can stimulate or inhibit the activity of a distant part 



of the biological system already formed. 

 HORMONE, MOBPHOGENETIC - term used by Neeiham to refer to Inductors which manifest distant effects. 

 HUMOBAl' SYSTEM - body fluids carrying specific chemical substances which may circulate in formed channels 

 (blood vessels or lymphatics) or diffuse freely in the body cavities or tissue spaces, (e.g., neuro- 

 humors of Parker which act on the pigmentary system) . 

 HYBBID - a successful cross between different species, although organism may be sterile (e.g., mule). 

 HYBRIDIZATION - fertilization of an egg by sperm of a different species. 



HYDBODYNAMICS - process by which the detailed architecture of the blood vessels is derived, such details 

 as size, angles or branching, courses to be followed, etc. The internal water pressure may be the 

 cause of specific developmental procedure. 

 HYALOPLASM - ground substance of the cell apart from the contained bodies. 

 HYPEBINNEEVATION - supplying an organ with more than a single (normal) nerve fiber. 

 HYPERMETAMORPHOSIS - protracted and complete metamorphosis. 

 HYPEEMORPHOSIS - overstepping previous ontogenies, though harmonious. 

 HYPERPLASIA - overgrowth; abnormal or unusual Increase in elements composing a part. 

 HYPEBTBOPHY - Increase in size due to increase in demands upon the part concerned. 

 HYPEBTROPHY COMPENSATORY - Increase In size of part or a whole organ due to the loss or removal of part 



or the'whole of an organ (generally hypertrophy in one member of the pair of organs). 

 HYPOMORPHIC - cells or tissues which are subordinate to formative processes (Heidenhain). 

 HYPOMOBPHOSIS - harmonious underdevelopment. ^ . ^ ^^ 



HYPOPHYSIS - an ectodermally derived solid (amphibia) or tubular (chick) structure arising anterior to the 

 stomodeum and growing inwardly toward the infundlbulum to give rise to the anterior and intermediate 

 parts of the pituitary gland. Syn"., Rathke's pocket (chick). 



