398 



DESCRIPTIONS OF THE PLATES. 



Figs. 29, 30. More mature condition in which the asci have begun to bud from the ascogenic 

 cell. tV 4. 



Fig. 31. Mature perithecium showing the ascogenic cell and the mass of asci developed from it 

 still supported by the two inferior supporting cells, which will soon be wholly destroyed, leaving the 

 ascus mass free within the cavity of the perithecium. ^ 2. 



Laboidbenia elongata Thaxter. 



Fig. 32. Young perithecium after fertilization, the insertion only of the trichogyne being 

 visible (tr). The carpogenic cell (f) has not yet divided. ^ 2. 



Fig. 33. The carpogenic cell has divided into the inferior and superior supporting cells and the 

 ascogonium. ^ 2. 



Fig. 34. The ascogenic apparatus seen at a stage slightly more advanced than in the previous 

 figure. The ascogonium has begun to grow upward on the right before the formation of septa. J 4. 



Fig. 35. Ascogenic apparatus in which the ascogonium has divided into two ascogenic cells 

 (ac) and a secondary inferior supporting cell (ist). J 4. 



Fig. 36. A more advanced stage, in which the asci (as) have begun to bud from the ascogenic 

 cells. J 4. Figs. 32-36 represent lateral views. 



Fig. 37. Antero-posterior view of the ascogenic apparatus, showing the two ascogenic cells lying 

 side by side and beginning to separate while the asci have already begun to bud. D 12. 



Fig. 38. Two ascogenic cells with asci attached seen as they lie free within the cavity of the 

 perithecium. That at the left seen dorsally, that at the right ventrally. J 2. 



Fig. 39. Ascogenic cell with attached asci seen sidewise as it lies free within the cavity of the 

 perithecium. J 2. 



A detailed description of the figures on this plate will be found on pages 218-228 of the text. 

 The letters correspond in all the figures, and the corresponding structures are as follows : (c) 

 primordial cell of perithecium proper ; (d) primordial cell of procarpe ; (o, o') basal cells of 

 perithecium ; (i, i, z) primordial cells of perithecial wall-cells, the parietal, and the canal-cells ; (f ) 

 carpogenic cell ; (e") trichophoric cell ; (e') base of trichogyne (tr) ; (nc', w, wx, wy, wz) wall-cells 

 of the perithecium; (wz) lip-cells; (pc) parietal cells of perithecium; (nc', cc, tc) canal-cells of peri- 

 thecium; (p) stalk-cell of perithecium; (h) secondary stalk-cell; (o') posterior basal cell; (o) one of 

 two anterior basal cells ; (nn) primordial wall-cells ; (am) ascogonium ; (is) inferior supporting cell ; 

 (ss) superior supporting cell ; (ist) secondary inferior supporting cell ; (ac) ascogenic cells ; (as) asci; 

 (sm) ascus mass. 



