Sexuality, etc., of the A.scocarp q/'Humaria granulata. 355 



comycete about 5 mm. in diameter, and of a yellow, orange or reddish tint, 

 is found growing on the dung of various animals, especially of cow, and 

 is most abundant during autumn and winter. The spores, apparently, 

 normally germinate only after they have passed through the alimentary 

 canal of the animal, for artificial cultures could not be obtained. A 

 preliminary peptic or tryptic digestion or a combination of both seemed to 

 have no effect on germination. Only a small number of experiments were 

 made in this direction, for by bringing the material into the laboratory, 

 natural cultures can sometimes be obtained, in which the fungus occurs in 

 such abundance in appropriate stages that the necessity for artificial cultures 

 is completely obviated. 



The material was chiefly fixed in Fleming's weak fluid, which was allowed 

 to act either for 24 hours or for one hour, fixation being completed in the 

 latter case with Merkel's fluid. Either safranin, gentian violet and orange, 

 or Benda's iron-heematoxylin were used for staining. The very youngest 

 stages of the apothecia are of course quite invisible, even with a powerful 

 hand-lens, but sections of them were secured by removing and fixing the 

 superficial layers of the substratum on which young apothecia were just 

 visible. The behaviour of the closely -packed nuclei of the ascogonium was 

 best followed in sections 4 //, in thickness. 



Vegetative mycelium. — The vegetative mycelium consists of cells which 

 show numerous nuclei, but these, unlike those of the ascogonium, are not 

 at all well marked, but appear generally as slightly staining homogeneous or 

 granular bodies which sometimes show a minute nucleolar dot (Plate 13, fig. 1). 



The cells of the whole vegetative mycelium and of the apothecium contain 

 a number of fairly large spherical granules, which stain deep red with the 

 safranin of the triple stain. In all the hyphse of the vegetative mycelium 

 and many of those of the ascocarp, these granules are found collected in 

 groups on opposite sides of the transverse walls (figs. 1 and 4). These 

 groups of granules were observed by Woronin (25) in this form and in 

 Ascobolvs, and by Harper (17) in Pyronema, but their function is unknown : 

 Harper has suggested that they may have something to do with the passage 

 of material from cell to cell through the wall. No reproductive organs other 

 than the apothecia were observed in connection with this form. 



Development of Apothecium. 



As long ago as 1866, Woronin (25) showed that the apothecium began by 

 the development of an archicarp as a side branch of an ordinary hypha o'f 

 the mycelium. He observed that the apical cell of this branch was round 

 and very much swollen, and that, later, side branches grew up from the cells 



