CHAPTER V. COMPARATIVE REVIEW. GASTROMYCETES. 



323 



two outer layers and of the inner wall of the peridium, so far as it surrounds the gleba, 

 advances part passu with the enlargement of the stipe. On the other hand, the tissue 

 in the cone and in the portion of the central column beneath the gleba diminishes 

 in proportion as the stipe enlarges, till at length in Ph. caninus (Fig. 153.7) it is only 

 a thin white membrane ; in Ph. impudicus it remains of larger size underneath the 

 gleba, forming a cup-shaped basal piece which supports the lower extremity of the 

 stipe (Fig. 154) ; in the cone it stretches into a thin white membrane, as in the other 

 species. The gleba, in which the formation of spores is completed or nearly completed 

 during the expansion of the stipe, dilates in Ph. caninus into a thin conical cap 

 covering the upper part of the stipe close beneath the extreme summit ; in Ph. impudicus 

 it diminishes less in thickness in proportion to the extension of its surface, and the 

 hyphae of the trama even manifest an active growth by the expansion of their cells. 

 No change in structure worth mentioning here occurs in the parts surrounding the 

 stipe during the time that it is enlarging beyond an evident increase in the size of the 

 hyphae. The cells of the parenchyma of the stipe itself continue thin-walled and 



FIG. 153. Phallus cttniniis. Young sporophore partly attached 

 to the mycelium m in median longitudinal section and natural size. 

 Succession of stages of development according to the letters y. 

 y a specimen not fully grown but with ripe spores ; a the outer wall. 

 ' the inner wall, g the gelatinous layer of the peridium, & the basal 

 portion, A the cone, s the stipe, gb the gleba. 



FIG. 154. Phallus impudicus. A nearly mature 

 example before the elongation of the stipe, in median 

 longitudinal section ; m mycelium, a outer, ' inner 

 wall, f gelatinous layer of the peridium, st stipe, h 

 its cavity filled with mucilage, / lower margin of the 

 pileus, sf gleba, the cup-shaped basal portion, 

 x the spot where the peridium is ruptured by the 

 elongation of the stipe. After Sachs. Two-thirds of 

 natural size. 



filled with a watery fluid. At length all growth by expansion of cells already formed 

 or by the formation of new ones comes to an end in all parts, and then comes a sudden 

 increase in the length of the stipe, which thrusts the gleba which is attached to its 

 summit against the apex of the peridium and bursting through it raises the gleba 

 high above it. The elongation is brought about simply by the raising and smoothing 

 out of the folds in the plates of parenchyma in the wall of the stipe, like the folds in 

 a paper hand-lantern, to repeat the comparison of the old botanist Schaffer, till 

 the length of the chambers is at least equal to the breadth ; the elongation of the 

 chambers is caused by accumulation of air within them and their consequent inflation. 

 The gelatinous felt which fills them at first is torn up and disappears, and the axile 

 gelatinous strand is also torn and replaced by air. This process takes place simul- 

 taneously at all points in Ph. impudicus ; in Ph. caninus it begins above and advances 

 slowly towards the base. The elongation of the stipe causes the inner peridium 

 of Ph. caninus to separate into two parts by an annular fissure beneath the gleba ; 

 the upper portion with the remains of the cone is carried upwards while the lower 



Y 2 



