DESCRIPTIONS OF THE PLATES. 



425 



DESCRIPTION OF PLATE XXIII. 



Zodiomyces vorticellarius Thaxter. 



Figs. 1-4. Young individuals in various stages of development. D 2. 



Fig. 5. Young individual. A cavity is forming above the perithecigerous cells. D 2. 



Fig. 6. Young individual, the upper portion of the receptacle seen in optical section. The end 

 of the primary appendage at the left has been broken off. The secondary appendages have burst 

 through the superficial cells at the apex of the receptacle, and the perithecia are beginning to arise 

 from the perithecigerous cells at the base of the cup-like cavity. D 2. 



Fig. 7. More mature individual, the optical section of its cup-like extremity indicated in part. 

 The primary appendage has disappeared, and one perithecium is nearly mature. A 12. 



Fig. 8. Mature individual. A 12. 



Fig. 9. Section of portion of extremity showing cup-like form, the secondary appendages on the 

 right arising from the inner surface of its rim distinct from the central fertile cells, from which arise 

 antheridia and perithecia in various stages of development. Drawn and partly reconstructed from 

 a microtome section. D 4. 



Figs. 10-12. Anterior, lateral, and posterior views of mature perithecia. D 4. 



Figs. 13-15. Very young perithecia, showing origin as terminal cell (fig. 13), and two further 

 divisions of this cell. J 4. 



Fig. 16. Young perithecium. J 4. 



Fig. 17. Young perithecium with trichogyne and conjugating antherozoid. Leitz oil -^ + 12. 

 Fig. 18. A similar stage. D 12. 



Fig. 19. Young perithecium before development of its appendages, lateral view. D 4. 

 Fig. 20. Young perithecium : its appendages beginning to bud out, posterior view. D 4. 

 Figs. 21-23. Antheridial branches, bearing exogenous antherozoids. D 12. 

 Fig. 24. Spore. D 4. 



Fig. 25. Young perithecium in which the ascogenic cell has divided, the trichogyne having 

 withered and broken off. J 4. 



