Dodge: Life History of Ascobolus magnificus 117 



a short distance apart ; one remains erect, the other elongates rap- 

 idly, forming a trichogyne which grows out and circles widely 

 about the antheridium, drawing it up into the coiled portion, the 

 end of which coils tightly about the end cell of the antheridium 

 and fuses with it (Text figs. 8, 10) . The habit of growing erect 

 on the surface of the medium is a hindrance to making photo- 

 graphs or camera lucida drawings of the primordia as they de- 

 velop. The ascogonia are always knocked over on the antheri- 

 dium and flattened down when a cover glass is used. 



It is not at all difficult to prove in every normal case that this 

 club-shaped antheridium is present. By using a high-powered 

 binocular microscope and a pair of the finest dissecting needles, 

 or needles made of glass drawn out, the antheridium can be 

 pulled out of the trichogyne coil provided fusion has not yet taken 

 place. In PI. 7, figs. 1 and 3, are shown photographs of a pair 

 of young primordia with different magnifications, and figs. 2 and 

 4 show the same pairs after the antheridium has been pulled out 

 of the encircling trichogyne coil. No fusion has taken place ; the 

 antheridium is plump and the contents are granular. An attempt 

 to separate the organs in later stages, that is, after fusion of the 

 cells, always results in a rupture of the trichogyne, sometimes 

 the break occurring adjacent to the ascogenous cell (PL 7, fig. 

 7). In most cases short hyphal branches soon grow out from 

 the stalk of the ascogonium and wrap about the stalk of the an- 

 theridium, so that it is impossible to separate the primordia (PL 

 7, figs. 5, 7, 8 and text fig. 8). This evidently is a further pro- 

 vision for maintaining the erect habit. It seems that there are 

 two phases in the life of this species when an abundance of air 

 is necessary, first at spore germination and second at the origin 

 of the ascocarps. Only those ascospores germinate that lie on 

 the surface of the medium and primordia never form beneath the 

 surface of the agar. A. Winteri and A. carbonarius are indif- 

 ferent to the amount of air at both of these periods. The asco- 

 genous cell, which can soon be recognized, begins to enlarge rap- 

 idly (Text figs. 7, 8, 9, and PL 7, fig. 9) and ascogenous hyphae 

 grow out in considerable numbers sometimes before sterile hy- 

 phae have begun to bud out to form the fruit body. (Text figs. 

 10, 13, 14, 15.) 



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