84 DIVISION T.-—GENERAL MORPHOLOGY. 
its sporangiophore and adheres by means of the gelatinous layer to foreign bodies, 
while the spores swell to their full extent and are disseminated. The sporangio- 
phore in these species! is a cell some millimetres in length, cylindrical in its middle 
portion, but inflated in its lower part and in its upper part especially just beneath 
the sporangium. It becomes more and more turgescent after the spores have 
matured and causes abjection of the sporangium by means of the mechanism 
described on page 72. The separation takes place in the line of an annular fissure, 
which is close beneath the insertion of the outer wall of the sporangium and is seen 
before the sporangium is flung off as a fine sharply marked line on the wall (Fig. 38). 
The delicate wall of the lower portion of the sporangium is ruptured at the moment 
of abjection, being struck by the ejected fluid, and thus the swelling of the gelatinous 
layer investing the spores is secured. 
The sporangium is sometimes abjected with considerable force. The sporangia 
of Pilobolus oedipus, in which species, according to Coemans and Brefeld, the greatest 
amount of force is exerted, are thrown, as we learn from the former authority, to a height 
of more than 1.05 M. The process, as Coemans has also proved, is greatly 
dependent on the amount of light. Under favourable circumstances the development 
of the sporangiophore begins at midday or in the afternoon ; it is completed and the 
sporangia and spores are also formed during the night, and the sporangium is thrown 
off during the following morning at an earlier or later hour according to the greater 
or less amount of light. Exclusion of light does not entirely prevent abjection but 
may delay it 12-15 hours. P. oedipus shows this sensitiveness to light and the 
normal periodicity to a less extent than P. crystallinus. We must not enter further 
in this place into the connection between these phenomena and the very strong positive 
heliotropism of the sporangiophore. 
The increasing turgescence of the sporangiferous cell before abjection, assuming that 
the superficial extent and elasticity of the membrane remain the same, may be 
caused either by increasing osmotic absorption of water on the part of the sporangiferous 
cell itself, or by the forcing of water from the mycelium into the passive sporangiferous cell, 
or by the combined operation of both these agencies. In my first edition I assumed 
that the latter of the two was the only operative cause, because a drop of water which 
increases in size is often seen to issue after abjection from the open sporangiferous cell 
before it finally collapses. More exact measurements are required for the confirmation 
of this view. 
Section XXI. The spores produced in asci and those of Protomyces 
macrosporus are set free in one of two ways according to the species; either by 
ejection ® (Ausschleuderung, Ejaculation) or by solution or gelatinous swelling (Auflösung, 
gallertige Verquellung) of the asci. 
The first process, the process of ejection, is found only in the case of spores 
which normally attain their full development inside the ascus. As they advance: 
towards this state, the protoplasm around them and the glycogen-mass subsequently 
formed constantly diminish in quantity, being doubtless used to a great extent as 
material for the formation of the spores. We are not at present in possession of more 

! Coemans in Mém. conc. de l’Acad. royale de Belgique, XXX.—J. Klein in Pringsheim’s 
Jahrb. VIII, p. 305.—Brefeld, Schimmelpilze, I and IV.—Van Tieghem, Mucorinées. See also the 
literature cited in sections XLI-XLIV. 
2 ‘Abjection’ and ‘ ejection’ have been adopted as renderings of ‘Abschlenderung’ and ‘ Ausschleu- 
derung,’ the throwing off or throwing out with force of spores from the sporogenous structure. 
