20 INTRODUCTION. 



most of the derivatives and compounds are formed from the Latin gaster. 

 Perhaps we should have adopted the latter as the technical designation for 

 the organ. 



33. Names and Abbreviations on the Figures. Whatever may 

 be the practice of different writers, probably all will agree that figures for the 

 information of students, and especially such as are to be used in dissection, 

 are more helpful if the following conditions are observed: 



1. So far as possible, the technical names of the parts should be written 

 upon the parts themselves. 



2. Where there is not room for the names upon the figure itself, they 

 should generally be written at the side, and connected with the parts by 

 distinct lines. 



3. When abbreviations are employed, they should be of the technical 

 rather than of the vernacular terms, and should be uniform, at least for all 

 figures of the same organ or region. 



Whoever examines the figures in the present work will see that an 

 attempt has been made to conform to the above named conditions. That 

 success has been only partial, will be at once anticipated and excused by all 

 who have undertaken the same task. The need of abbreviation was greatest 

 with the brain, where many distinct parts are crowded within a small space. 

 Here, as a rule, only names of more general application, such as Fissura, 

 Gyrus, Sulcus, etc., and their abbreviations, have been commenced with 

 capitals ; but this distinction has not been observed in all other cases. 



In the explanations of the figures, the abbreviations are given in alpha- 

 betical order. 



34. Terms of Position and Direction Toponymy. Like other 

 solids, the body of an animal has six general aspects. 



As with other elongated solids, these aspects are two ends and 

 four sides. 



Were the body simply a mass of homogeneous material, like, for 

 example, an oval of wood, the supporting side would be called the bottom, 

 and described as the lower side; the opposite side would then be upper, and 

 be called top ; of the two other sides, either might be called right, and the 

 opposite would then be left; finally, either of the two ends might be 

 named front, and the other end would then be known as back. To indicate 

 the two ends as anterior and posterior, and the top and bottom as superior 

 and inferior, would render only more evident the fact that the various 

 aspects of the mass are determined and named according to their relations 

 to the observer, or to the surface of the earth. 



But with the animal body, at least the body of the adult vertebrate, 

 there are constant and more or less marked distinctions between the 

 opposite ends and sides, so that these various aspects have fixed and definite 

 relations to one another and to certain other objects or influences. 



