l66 BOTANICAL GAZETTE [February 



Actinomyces V 



Fig. 21. — Aerial hypha with spiral termination and 2 fertile branches, 

 more mature elements showing failure of spore to develop in proximal portion. 



Fig. 22. — Aerial hypha with 2 spiral elements. 



Fig. 23. — Young spiral branch of 15 turns attached to axial hypha con- 

 taining metachromatic granules. 



Figs. 24-26. — Spiral branches soon after insertion of septa, showing cross- 

 walls absent from portion above basal septum. 



Fig. 27. — Young spiral branch. 



Figs. 29, 30. — Spiral branches with spores mature, and non-septate portion 

 completely evacuated. 



Figs. 31, 32. — Degenerate filaments containing much metachromatic 

 material. 



Actinomyces VI 



Fig. S3- — Portion of aerial mycelium showing 2 spiral elements with nuclei 

 in mature spores of one; septum in axial filament associated with basal septum 

 in branch. 



Fig. 34. — Similar to fig. ^^j but without visible nuclei. 



Figs. 35-37. — Other portions of aerial mycelium. 



Actinomyces VII 



Figs. 38-40. — Portions of aerial mycelium with sporogenous branches in 

 various stages of development. 



PL ATE. IV 



Actinomyces VIII 



Fig. 41. — Sporogenous apparatus with mature spores cohering in zoogloea- 

 like masses. 



Fig. 42. — Prostrate hypha containing numerous metachromatic granules 

 and bearing a branch with many crowded spiral ramifications. 



Fig. 43. — More open type of sporogenous apparatus with lateral elements 

 attached to axial hypha at intervals. 



Fig. 44. — Young sporogenous apparatus with spiral branches more or less 

 crowded. 



Fig. 45. — Somewhat older system of spiral hyphae, some of which have 

 become converted into zoogloea-like masses of spores. 



Fig. 46. — ^Lateral element bearing 8 spiral branches. 



Figs. 47, 48. — Portions of degenerate mycelium showing Leptomitiis-Wkt 

 enlargements occupied by vacuoles, and metachromatic granules in con- 

 strictions. 



Figs. 49, 50. — Spores germinating with i germ tube. 



