FUNGI 
227 
be 10 to 15/x thick; to show details of nuclei, 3 /z is thick enough 
(Fig. 64). 
In Hydnum and Polyporus , cut out pieces about 3 or 4 spines or 
3 or 4 pores in width and about 1 cm. long. A rectangular piece 
which will allow the transverse 
sections of the spines or pores to 
be about 4 mm. wide and 1 cm. 
long cuts better than a piece which 
will give square sections. 
In Boletus , simply strip off 
the hymenium and cut into pieces 
which will give transverse sections 
of the tubes. 
In Lycoperdon, Bovista , 
Geaster , and Scleroderma , longi¬ 
tudinal sections of the entire 
fructification can be cut in paraf¬ 
fin as long as the fresh material is 
easily sliced with a Gillette blade. 
Young stages of Cyathus, Cru- 
cibulum, and Nidularia cut easily 
in paraffin; somewhat older stages 
can be cut in celloidin, but mature 
stages fail to cut by any of our 
present methods. 
It is often desirable to secure 
differential staining of the fungus 
and its host. Some of the methods previously mentioned secure 
this result and give excellent detail, but do not make the mycelium 
stand out sharply in contrast with the tissues of the host. A special 
method by B. T. Dickson generally gives a good differentiation. He 
uses Magdala red and light green, using the Magdala red in a 2 per 
cent solution in 85 per cent alcohol, and the light green in a 2 per cent 
solution in clove oil to which has been added a few drops of abso¬ 
lute alcohol. His schedule is as follows: 
Fig. 64.— Coprinus: young basidia with 
four nuclei which, later, pass into the spores; 
fixed in chromo-acetic acid and stained in 
safranin, gentian-violet, orange. X780. 
1. Dissolve paraffin in xylol and wash in absolute alcohol. 
2. Wash in 95 and 85 per cent alcohol. 
3. Stain with Magdala red 5 to 10 minutes. 
4. Remove surplus stain and wash in 95 per cent alcohol. 
