EERORS 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 in his especial depart- 

 ment of microscopy, we recommend Dr. Beale's book 

 on " The Microscope, and its Application to Clinical 

 Medicine." 1 - 



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 otr 

 eyes play us that trick 1 ? but that it should reveal so 

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



(1) The Cyclopaedia 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, of 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 



