No. 387.] THE PRESENT STATUS OF ANATOMY. 187 
fections of the compound microscope were overcome and the 
instrument we now so constantly employ was within reach. 
But, after all, the microscope, per se, in anatomy has enormous 
limitations. A fragment of tissue taken from the body and 
placed at once beneath the strongest powers of the microscope 
yields but few of its secrets. The great development in the 
modern use of the microscope, if I may so express myself, has 
been in the methods of preparation of the tissues to be exam- 
ined, methods which have become so familiar to workers with 
the microscope that they are apt to forget how very recent they 
are. The hardening of tissues was not introduced until the 
beginning of the present century (Reil), and then alcohol alone 
was used; the processes of “fixation” previous to hardening 
had their origin in the discovery of the value of osmic acid for 
this purpose by Max Schultze in 1864; section cutting, even 
free-hand, was not generally employed until after the middle 
of the present century; staining was first employed by Ger- 
lach in 1858; and mounting in refractive media was introduced 
by Stilling about the same time as section cutting (1840). 
How rapid, then, has been the development of our modern 
methods! To-day instead of one “ fixative ” we have our choice 
of many; instead of cutting our sections with the free-hand 
and spoiling many, we have instruments of precision by which 
we can cut an entire organism ora piece of tissue into sections 
zggy of an inch in thickness without spoiling one, and, if 
necessary, can obtain sections of suber OF even gzbov of an 
inch, so perfect have our methods become. While Gerlach 
knew only one medium for staining, namely, carmine, to-day 
we have dozens, the discovery of the anilines placing in our 
hands a marvelous aid to microscopical investigation. By 
their use we can differentiate tissues. One dye will have an 
affinity for nerve tissue, another for yellow elastic tissue, 
another for mucin; others will affect most strongly the chrom- 
atin of the cell nucleus, others the cell body or cytoplasm, and 
so on; and thus, by choosing the proper method, it is possible 
to differentiate structures in a most marvelous manner. 
So then the anatomist of to-day, by the proper employment 
of the methods at his disposal, has it in his power to make 
