WITH THE MICROSCOPE. 28 1 



right to work as he likes to praise any processes of investigation 

 which he believes to be advantageous and condemn those he con- 

 siders objectionable. Unfortunately, however, some anatomists 

 endeavour to disparage the means of research which they cannot 

 or will not employ. There are observers who will not admit that 

 the simplest and only efficient manner of introducing fluid into all 

 parts of a tissue is to inject it by the vessels, and there are indi- 

 viduals who will maintain that those appearances can alone be 

 trusted, and accepted, as natural appearances, which result from 

 observations' upon tissues immersed in water. 



It is indeed most certainly true, that nothing is gained by sub- 

 jecting specimens immersed in water to the highest powers. No 

 wonder, therefore, that authorities who entertain this opinion should 

 assert that high powers are useless. But it has been distinctly proved 

 that water alters many tissues extremely, and completely destroys 

 some of the most delicate textures. Its limpid character renders it 

 impossible to fray out many delicate tissues immersed in it, or to 

 subject them without complete destruction to the amount of pressure 

 sufficient to make them thin enough for observation with high powers. 

 Notwithstanding all this, not a few observers still use water and 

 solutions of which water is the principal ingredient, and refuse to 

 adopt or admit any principles opposed to this plan. Not content 

 with working on in their own way, some of these observers do all 

 they can to underrate the importance of observations made upon any 

 other principles. If anyone makes out new points of structure by 

 any new method, all that an authority who differs has to do in order 

 to upset his views, is to state that he has not been able to see the 

 structure described. If an authority simply denies the existence of 

 what he has himself been unable to see, he is but too often implicitly 

 believed, although he may not have taken the pains to try the only 

 method of investigation by which the appearances in question could 

 be seen. Some writers without having ever seen points of structure 

 described by others, and without denying the truth of their obser- 

 vations, content themselves with intimating that the new notions are 

 not likely to be true, because " such an arrangement does not exist 

 in the corresponding tissue of a particular animal closely allied to 

 the one in question," which they have elaborately studied. 



Only recently an article has appeared in a well-known journal, in 

 which it is asserted, as an argument against the employment of high 

 powers, that all the important discoveries in natural history and 

 anatomy have been made with the aid of powers which do not mag- 

 nify more than the quarter .of an inch object-glass (200 diameters). 

 It is only necessary to remark that the writer of this remarkable 



