— 119 — 



any instrument, a large quantity of small, light knots scattered 

 over the nourishing medium. These knots, young perithecia, are 

 already thickly entwined by sterile hyphae. The latter rise out of the 

 hypha, bearing the ascogonium, and from the neighbouring hyphae 

 (fig. 3, 4). One cell often carries several outgrowths, twisting in 

 different directions and thus surrouding the perithecia on all sides. 

 Therefore the entwining of the ascogonium proceeds extremely ra- 

 pidly. In the centre of a young perithecium, cleared and stained 

 as described above (see p. 117), one may already notice a large 

 spiral coiled thread. As the sheath of the perithecium continues to 

 develop quickly, and begins to get fawn coloured, further observa- 

 tions of the whole perithecium have to be abandoned, and one is 

 obliged to turn for this purpose to preparations. On microtomed 

 sections (usually cut from 6 — 12 ]i thick) of a young perithecium 

 one could observe, that it consists of a sheath, formed of two or 

 three layers of cells, closely touching each other, and of an asco- 

 gonium. The latter generally, has the same appearance of a coiled 

 spiral. Its cells, tilled with dense contents have considerably grown 

 in size. On fig. 5 you see distinctly that in the ascogonium, at this 

 stage of development, a certain differentiation of cells also takes 

 place: the lower cell, without stretching in length, becomes very 

 лvide, as if swollen, and only the other cells, lengthen out. 



Approximately on the twelfth or thirteenth day of the develop- 

 ment of the fungus the spherical perithecia begin to lengthen 

 slightly and take the shape of a pear. At this stage of development 

 the ascogonial cells, all or some, a fact which is not yet cleared, 

 give side branches — the ascogenous hyphae (figs. 6,7). At first they 

 are few, but afterwards according to the development of the fun- 

 gus and growth of the cells of the ascogonium, the number of the 

 ascogenous hyphae also greatly increases. Moreover, they begin 

 immediately to send out branches in profusion and form in a short 

 time such thick masses, that it becomes difficult to distinguish the 

 individual cells of the ascogonium. Branching and growing in all 

 directions, the ascogenous hyphae bend over at the tips and form 

 the characteristic bent end, from the penultimate cell of which the 

 ascus is then formed (fig. 9). The fig. 10, representing a longitu- 

 dinal section made by hand, through a living perithecium, shows 

 one ascogenous hyphae, bearing a young ascus on its end. In the 



