ANIMAL STRUCTURES MODE OF INVESTIGATING. 585 



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 department 

 of microscopy, we recommend an excellent little book by 

 Dr. Beale, " The Microscope, and its Application to Clinical 

 Medicine." l 



The importance of becoming thoroughly familiar with the 

 structural and microscopical characters of any particular 

 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 descriptions 

 of morbid appearances. All who wish to use the micro- 

 scope successfully, with reference to the examinations of 

 organs in a diseased state, will do well to acquaint them- 

 selves 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 Cyclopaedia of Anatomy and Physiology will be found a most valu- 

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

 minute anatomy. A valuable paper appears in the Medico-Chur. Review, 

 Oct. 1857, from the pen of Mr. G. Rainey, M.R.C.S. : " On the Formation of the 

 Skeletons of Animals and other hard Structures formed in connexion with Living 

 Tissues." Also consult Dr. Lankester's translation of Dr. Kiichenmeister's 

 " Animal and Vegetable Parasites of the Human Body." Published by the 

 Sydenham Society, 1857. 



