present to the eye a group of items having 

 in common some fundamental relationship. 

 An author-list throws together on the 

 printed page works entirely without rela- 

 tion to each other beyond the alphabetical 

 accident of the authors' parentage. This ob- 

 jection is particularly weighty when we have 

 to deal with such diverse materials as those 

 included in this bibliography. For these 

 reasons we have made subject the primary 

 basis for classification. On the other hand, 

 wherever some other basis of classification 

 seemed more suitable it has been used. For 

 example, the literature to the beginning of 

 the 19th Century has been arranged chron- 

 ologically in three sections. Again, when 

 structure or function does not lend itself to 

 further subdivision, we have resorted to the 

 species of animals studied for the basis of a 

 finer classification. This has been done, for 

 example, in "Habits in nature and captivity" 

 and in certain of the anatomical sections 

 where an organ as a whole {e.g., the con- 

 figurational pattern of the cerebral cortex) 

 has been extensively studied. Those ad- 

 vantages inherent in an arrangement by 

 authors can be largely gained by an index 

 of authors, which has been provided. 



Having chosen to make structure the 

 basis of classification of anatomical studies, 

 the difficulty arises that a printed list is a 

 strictly unidimensional frame into which 

 must be fitted studies which have at least 

 two parameters. If a system and its sub- 

 divisions into organs is regarded as one par- 

 ameter, a given study is also classifiable 

 according to a second dimension, which is 

 the aspect of the structure investigated. 

 Along this dimension are found gross anat- 

 omy, minute anatomy or histology, devel- 

 opment and growth, variations and anoma- 

 lies, and quantitative aspects studied by 

 the techniques of physical anthropology. 

 It is obvious that this is a true parameter 

 because the body as a whole, a system, or 

 an organ can be approached from any of 

 these points of view. It was considered de- 

 sirable to classify according to this param- 

 eter in a subsidiary fashion. Therefore the 

 chapter devoted to a system, and to smaller 



units than a system wherever justified by 

 the volume of literature, is opened with an 

 expansion for embryology, histology, di- 

 mensions and weights, etc. In certain sec- 

 tions, only cross reference numbers appear 

 under these headings. Where the structural 

 unit involved is a single organ or a bone we 

 have followed the practice of entering such 

 a paper under the structure and cross refer- 

 encing to Histology, Embryology, or similar 

 rubrics at the beginning of the section. This 

 was done to avoid the confusion arising 

 from over-fragmentation of the literature. 



Obviously many papers could be placed 

 under more than one topic heading. The 

 item is printed in full under the topic which 

 seems to be the main theme of the paper, 

 though sometimes this decision is difficult. 

 Subsidiary themes are honored by listing 

 the serial number at the end of the section 

 devoted to that subject. Each section there- 

 fore consists of a list of items printed in full, 

 followed by a list of serial numbers that 

 leads the reader to further literature of the 

 subject. The extent to which monographs 

 or articles which deal comprehensively with 

 a system as a whole should be cross refer- 

 enced presents a difficult problem. There 

 seems little to be gained in cross referenc- 

 ing such an article to each of the dozens of 

 smaller topics with which it treats. Instead, 

 such works are grouped together under the 

 heading Comprehensive and general studies 

 and constitute the first section for each 

 chapter. Similarly, works dealing in a com- 

 prehensive fashion with the body as a whole 

 form the first chapter of the anatomical 

 section after the opening chapter on em- 

 bryology. Articles which are general in 

 point of view or not truly comprehensive in 

 scope tend to be cross referenced more, de- 

 spite their lesser value, than works easily 

 recognized as extensive monographs. 



In the preliminary classification of litera- 

 ture in anatomy and physiology the com- 

 pact, decimal notation provided by the 

 Classification decimale universelle, Bruxelles, 

 1927-29, proved extremely useful. The final 

 arrangement has departed somewhat from 

 the Bruxelles scheme for anatomy and con- 



Ixvi] 



