EKEORS OF INTERPRETATION. 723 



general survey of the whole fabric. Such a survey will 

 not be unattended with its difficulties and disappoint- 

 ments, but it will bring its own reward for any amount 

 of labour bestowed. To the medical student, desirous 

 of obtaining further information, I would recommend 

 Klein and Sanderson's " Handbook for the Physiological 

 Laboratory," and Dr. Stirling's " Text- Book of Prac- 

 tical Histology." 



The importance of becoming thoroughly familiar with 

 the structural and microscopical characters of any par- 

 ticular organ in a healthy condition, cannot be too strongly 

 urged upon the attention of the student ; as to a want of 

 this knowledge must be attributed many erroneous de- 

 scriptions of morbid appearances. All who wish to use 

 the microscope successfully, with reference to the exami- 

 nation of organs in a diseased state, will do well to 

 acquaint themselves with minute anatomy generally, not 

 only of the human subject, but of the lower animals ; 

 without such knowledge it will be found impossible to 

 study pathology, or prosecute pathological inquiries with 

 any degree of success. 



A large amount of wrong observation has been recorded 

 on cells and cellular structures : since Schwann announced 

 his "cell theory," almost everything round has been 

 regarded as a cell ; any single body within this, or where 

 there are several, the largest, has been regarded as a 

 nucleus, and any spot within the nucleus has been viewed 

 as a nucleolus. Whereas many of the so-called cells are 

 homogeneous spheres; many of the nuclei are vacuoles, 

 and so forth. 



Such errors are natural, at first inevitable ; they can be 

 corrected only by practice, by testing observations in other 

 ways, especially by chemical re-agents, and by comparison 

 with the observations of others. " The marvel is not that 

 the microscope should suggest false views do not our 

 eyes play us that trick? but that it should reveal so 

 many astounding facts as it really does ; and the one con- 



(1) The Cyclopedia of Anatomy and Physiology will be found a most valuable 

 book of reference for the student in all matters relating to physiology and 

 minute anatomy. Numerous valuable papers are distributed throughout the 

 Trans, cf the Royal Micros. Soc. : Huxley's Lectures on Comparative Anatomy 

 Owen's lectures on Comparative Anatomy ; Carpenter's Physiology, edited by H. 

 Power, and Kolliker's Manual of Human Microscopic Anatomy. 



3 A2 



