PREFACE. 



THE preparation of the eighth edition was undertaken in response to 

 repeated requests from teachers, and was influenced by the aim stated in the 

 original preface : to present descriptions which should include the salient 

 features of the various structures with sufficient fulness to impress important 

 details without wearying minutiae ; too great conciseness, on the one hand, 

 and too great elaboration of detail, on the other, are alike unsatisfactory. 



The fact that histology has its place at the beginning of the medical 

 curriculum, and, indeed, with increasing frequency in the courses preparatory 

 to medicine, often requires the student to study the microscopic details of 

 organs before he has become acquainted with their gross anatomy. In order 

 to minimize this deficiency, the histological descriptions have been prefaced 

 with references to the macroscopic features whenever such explanations 

 seemed desirable. The criticism, for instance, that an outline description of 

 the brain, by pencil as well as by pen, is out of place in a text-book of his- 

 tology, loses much of its force when the usual ignorance of the student con- 

 cerning even the chief subdivisions of the central nervous system is recalled. 

 The author believes, therefore, that these additions are justified and will ma- 

 terially facilitate the student's appreciation of the correlation between the 

 structures demonstrated in the dissecting room and the details seen under 

 the microscope. 



With the exception of those from other sources, duly acknowledged in 

 the legends, the illustrations have been drawn, with the aid of the camera 

 lucida, by Mr. Louis Schmidt, whose skilful pencil has faithfully represented 

 the preparations. The latter, mostly from the author's cabinet, have been 

 selected to show the usual rather than the unusual histological appearances. 



The author gratefully acknowledges the kindness of Prof. William G. 

 Spiller, Prof. G. Carl Huber, Prof. Thomas G. Lee, and Dr. Joseph P. Tunis 

 in placing their preparations at his disposal. To Dr. W. H. F. Addison 

 his thanks are due for repeated courtesies in preparing specimens and for 

 suggestions regarding microscopical technique. The author wishes to ex- 

 press his obligations to the publishers for their hearty cooperation. 



UNIVERSITY OF PENNSYLVANIA, 



August, 1910. 



ill 



