SUBJECT INDEX 



New Headings 



Abortions & embryonic death 



Electric organ 



Free radical 



Neuroglia 



Optic centre & tracts 



Ribonucleoprotein 



(alphabetical order) 



Headings Cancelled 

 Cell cycle (see Cell) 

 Cell death (see Cell) 

 Cell fusion (see Cell) 

 Cell heredity (see Cell) 

 Cell wall (see Cell) 

 Chimeras (see Genetics) 

 Cytogenetics (see Chromosome) 

 InsuUn (see Hormones (vertebrates)) 

 Matrix (see Cell) 

 Membrane (see Cell) 

 Thyroxine (see Hormones (vertebrates)) 



All research subjects in the Directory of Names and Addresses are represented by at 

 least one entry. The names of investigators refer back to that Directory. Since initials of 

 first names are omitted from the entries, it may sometimes be necessary to check two or 

 more investigators of the same surname in the Directory of Names. 



Headings are printed in capitals. They generally come under one of the following cate- 

 gories: 



1) Structures, e.g. organs, tissues, cells 



2) Substances or classes of substances 



3) Developmental stages, processes, and factors (including Metamorphosis, Regeneration, 

 Genetics (developmental). Reproduction, Pathology (developmental)) 



4) Techniques appearing as headings are: Chemical microanalysis. Culture & preservation, 

 Immunochemistry, Irradiation, Microcinematography, Rearing methods. Transfer 

 (Blastocyst, etc.). Transplantation, Ultraviolet irradiation, Vital staining, X-irradiation. 



5) General subjects: History, Theoretical biology. 



Headings are extensively cross-referenced, but not usually from lower-order to higher- 

 order categories. 



When a term is referenced to another heading this does not always mean that in this 

 issue entries under this heading do indeed refer to the term in question. 



Contrary to former practice many headings only show animal and plant names. Com- 

 paratively few headings are divided into subheadings but lack organism names. The num- 

 ber of references under each of the subheadings or organism groups can be rather large, 

 but care has been taken not to exceed 50 investigators' names. 



Subheadings (if used) are mostly chosen from the following classes of terms: 



1) Character of investigation: descriptive, experimental, genetical, cell biological, etc. 



2) Stages: gametes, embryo, etc. 



3) Organ systems, also placenta, tumours, etc. 



4) Developmental processes: differentiation, regeneration, reproduction, teratogenesis, 

 etc. 



5) Organism groups other than vertebrates: unicellular organisms, plants, invertebrates. If 

 these subheadings are used all the work on the groups in question is indexed only here, 

 not elsewhere. 



Subheadings not belonging to the above classes are to be found under the following 

 headings: Cell, Chemical elements, Chromosome, Gene, Genetics, Hormones (vertebrates), 

 Mutant, Subcellular components, Teratogenesis. 



In general subheadings are chosen to encompass a rather broad range of subjects. 



Work falling under three or more of the subheadings, or not clearly defined, is classed 

 under the subheading "general, miscellaneous and unspecified" which is not placed alpha- 

 betically but immediately following the heading. 



Animal and Plant Names 



Generally Classes (and in some cases Phyla) are used. Exceptions are: the use of Homo 



151 



