1896 | THE PHALLOIDEAE OF THE UNITED STATES 277 
medullary system, as they have been heretofore.3 As shown in 
this stage the manner of formation of these lobes seems to be 
that of a general growth of medullary hyphe along three or 
four longitudinal lines outward among the cortical hyphe of 
the layer C of the youngest stage. That this is the actual mode 
of formation of the lobes is shown by the fact that their margi- 
nal portions are less sharply set off from the cortical layer than 
is the case in later, and even earlier stages. In this stage many 
cortical hyphz can be followed into the marginal portions of the 
lobes, and the color reactions by the double stain used are less 
sharp in those portions than they are between the cortical and 
medullary systems in other stages. 
It is to be observed that in this stage the surface of the egg 
does not conform to the surface of the medullary portion, but 
has in cross-section the nearly circular outline of the youngest 
stage (fig. 2). In later stages a gelatinous accumulation in the 
lobes (G, G) causes them to swell outward and laterally towards 
each other so as to give to the egg a surface with a broad 
rounded longitudinal ridge, extending outside of each lobe from 
the base of the egg nearly to its apex. These lobes are separa- 
ted by shallow furrows, each of which marks the position of a 
column of the receptaculum, and is of great help in orienting 
the eggs for sectioning. Were such longitudinal ridges and fur- 
FOWs present on the surface of the egg in the stage of fig. 2, they 
would have favored the view which I formerly held that the 
medullary lobes originate by outward protrusion of medullary 
tissue along four longitudinal lines, such protrusion being due to 
“§0rous growth within the medullary portion merely pushing 
the cortical layer further outward in those regions. 
The columns of the receptaculum arise in the angles (C0) 
between the medullary lobes (G, figs. 3 and g). Ed. Fischer+ 
in his Study of Clathrus cancellatus has called the tissue C’ of these 
angles Zwischengeflecht, and has referred it to the medullary sys- 
3G 
q 
MOR On Sn ee ee ee 
in - Ed. Fischer, Untersuchungen z. vergleich. Entwicklungsgeschichte u Sys- 
B ae Phalloideen, Denkschr. d. Schweiz. naturf. Gesellsch. 32:4. 1890; also 
mt on Anthurus, /. ¢, 494. 
‘ Ibid. 4, 
