vi PREFACE 



In the most recent text-books of neurology and in the atlas of Golgi these facts have 

 been shown by drawings and diagrams. But all such drawings are necessarily imperfect and 

 involve a personal element of interpretation. It has seemed to me, therefore, that a series of 

 photographs presenting the actual appearance of neurons under the microscope would be not 

 only of interest but also of service to students. The Golgi method lends itself very readily 

 to the photographic process, for the cell with its dendrites and neuraxon is stained black 

 upon a light yellowish ground, and thus is capable of giving a sharp picture. In the prepa- 

 ration of this atlas I have had the cooperation of Dr. O. S. Strong, who has cut and 

 stained the specimens, and of Dr. Edward Learning, whose skill in photography has made this 

 work possible. Dr. Strong has been able to produce remarkably successful sections of the 

 various parts of the nervous system, both brain and spinal cord, and has made some valuable 

 modifications of Golgi's methods. He has contributed a section upon the technique contain- 

 ing many original and important suggestions. In the art of photographing microscopic speci- 

 mens Dr. Learning has been particularly successful. It can be readily imagined that the 

 difficulties of obtaining a clear picture focussed in one plane upon the photographic plate are 

 at times almost insuperable, the microscopist ordinarily bringing various planes into his vision 

 by the aid of the fine adjusting screw of the instrument. By care in the selection of speci- 

 mens, by ingenious contrivances to insure a perfect focussing, and by the use of various 

 methods adapted to each emergency, Dr. Learning has succeeded where others have failed. 

 He has contributed a section of much value upon the photographic technique. The photo- 

 graphs have been reproduced in a painstaking manner by Mr. Edward Bierstadt, whose 

 process of artotyping has been selected after a careful comparison with other methods of 

 reproduction; and it can be justly said that they show every detail of the original photo- 

 graphs. 



In preparing this atlas I have not attempted to write an exhaustive account of nerve 

 histology, but rather to present a brief review of the essential facts which can be demon- 

 strated by the aid of the Golgi stain, and to show how these facts aid in the knowledge of 

 nervous action. There are other methods of investigation, notably the method of Nissl, which 

 cannot be demonstrated by photography, and which reveal facts of equal importance, but these 

 must be sought elsewhere. I may be permitted, however, to point out that this atlas is based 

 mainly upon preparations from the human nervous system ; that it not only includes the 

 spinal cord, cerebellum, and brain cortex, which have been studied by Golgi, Cajal, Van 

 Gehuchten, Retzius, and Lenhossek, but also presents original studies of the corpora quadri- 

 gemina, optic thalamus, and lenticular and caudate nuclei, and is thus quite complete in its 

 scope. It is my intention at some future time to issue another volume which will include 

 .the peripheral nerves and their terminations and the organs of sense. 



M. ALLEN STARR. 



