122 Murphy.-—The Morphology and Cytology of the 
microscope. No attempt was made to differentiate with absolute alcohol: 
although the process is slower with clove oil the latter extracts the stain 
better from the cytoplasm, bringing out the orange G and giving a clearer 
and more pleasing picture. This is especially valuable in the young 
oogonium, where the cytoplasm has a strong affinity for gentian violet. 
The clove oil was followed by cedar oil, all the former being carefully 
removed, and then the slide was allowed to drain and mounted in balsam. 
This formula works excellently on other Fungi also without modification. 
Other formulae may be used, and were much used before this one was hit 
upon, but they do not give as good results. 
Many other stains and combinations were tried, particularly in the 
attempt to stain fertilization tubes. These included light green, eosin, 
erythrosin, cyanin, acid fuchsin, and methyl green. None of them proved 
a success, although it is probable that acid fuchsin would have made 
a good stain for the fertilization tube had there been a little more material 
at hand to experiment upon. 
Development of the Sexual Organs. 
Penetration of the antheridium by the oogonial incept. 
In sections prepared from cultures on oat agar about four days old 
there are no sexual organs of the familiar mature type. Here and there, 
however, there will be found on the mycelium exceedingly small swellings 
which are very retentive of safranin and show no details unless that stain be 
well washed out. Under the oil immersion structures like those shown in 
Plate II, Figs. 2 to 8 are seen. A more or less irregularly spherical body, 
the wall of which stains deeply with orange G, is found constantly in close 
relation to another organ of a club-like shape which has an affinity for 
safranin and gentian violet. The two bodies are borne on separate 
hyphae and are clearly of independent origin. The orange body preserves 
the same staining reaction all through and is evidently the antheridium. 
The other, which we shall call the oogonial incept, after Pethybridge 
( 27 )—assuming for the moment that it is such—when cut in the direction 
of its long axis, seems to lie either within the antheridium or very closely 
applied to it. 
The evidence that it is within it is grouped under the following 
heads: 
1. Careful focusing shows that parts of the antheridium lie above as 
well as below the club-shaped oogonial incept when viewed in 
longitudinal section (Figs. 2 and 3). 
2. A section in the plane at right angles to the long axis, or a cross- 
section, shows one circular body within another (Fig. 4, a). The 
wall of the outer stains yellow; it is the antheridium. The inner 
