6 
In addition to MAut’s reticulum stain, I have found that splendid 
results can be obtained with the following mixture: 
Nigrosin 4 gms. 
Water 100 ccm. 
A few drops of this solution is allowed to remain in the section 
for 15 to 20 minutes. It is then washed in 70°/, alcohol, transferred 
to absolute alcohol, cleared in xylol, and mounted in balsam. The 
picture afforded by this stain is very sharp and it does not fade as 
quickly as the fuchsin. 
The tissue for the SPALTEHOLZ method is fixed in 1°/, solution 
of mercuric chloride in 33°/, alcohol for 24 hours. The strength of 
the alcohol is then increased about 10°/, every 24 hours until the 
tissue reaches absolute alcohol when it can be transferred to creosote, 
xylol and embedded in paraffin in the usual way. Serial sections 
about 6 w thick are cut and the alternate sections arranged in two 
series, the one for digestion and the other for control staining. The 
sections to be digested are firmly fixed on the slide by the water 
method and after the paraffin has been dissolved, they are allowed to 
remain in benzine for 24 hours. The slides with the sections are 
then submitted to the action of an artificial pancreatic juice for 6 to 
12 hours when they are removed, washed and stained. 
When digested, frozen sections of the adrenal are treated with 
dilute acids, the reticulum swells and becomes transparent but the 
transparency of the fibrils, however, is not as marked as that obtained 
when white fibres are submitted to the same treatment. If the pro- 
cess is allowed to go on under the microscope the former sharp 
contour of the fibrils is brought back by the exertion of a slight 
pressure on the cover glass. In making the following tests frozen 
sections of tendon, adrenal, and lymph gland were taken from the 
same dog, my object being to compare the behavior of the framework 
of the adrenal with the white fibrous tissue of the tendo Achillis, on 
the one hand, and the reticulum of the lymph gland on the other. 
The sections were kept under precisely the same conditions throughout 
the experiment. They were digested in pancreatin 24 hours, washed 
and shaken in distilled water and then allowed to remain in the acid 
or in the alkali solutions 2 hours before boiling. The figures repre- 
sent the average of two experiments and the time was not taken until 
the temperature had reached 99,5° C. 
