1 919] DRECHSLER— ACTINOMYCES 165 



20. Sauvageau, C, and Radais, M., Sur le genre Cladothrix. Ann. de 1' Inst. 

 Pasteur 6:242-273. 1892. 



21. ScHUTZE, H., Beitrage zur Kenntnis der thermophilen Aktinomyzeten und 

 ihre Sporenbildung. Arch. Hygiene 67:35-56. 1908. 



22. Thaxter, R., The potato scab. Conn. Sta. Rep. 15:153-160. 1892. 



23. Waksman, S. a., and Curtis, R. E., The Actinomyces of the soil. Soil 

 Science 1:99-134. 1916. 



24. Wolff, M., and Isr-Ael, J., tjber Reinkulturen des Actinomyces und seine 

 Ubertragbarkeit auf Thiere. Virchow's Archiv. 126:11-59. 1891. 



EXPLANATION OF PLATES II-IX 



All except figs. 7, 8, 70, and loi, which are semidiagrammatical repre- 

 sentations with a magnification of approximately 8000, were drawn with the 

 aid of a camera lucida with a magnification of 2750. 



PLATE II 



Actinomyces I 



Fig. I. — Moderately well developed fructification. 



Fig. 2. — Somewhat smaller fructification showing successive order of 

 development: a, chain of spores, largely disrupted, developed from termination 

 of axial hypha; b, c, d, secondary branches that have given rise respectively to 

 series of elements bi-b4, ci-cj, and di-dj. 



Fig. 3. — Spore germinating with 4 germ tubes. 



Actinomyces II 



Figs. 4-6. — Portions of aerial mycelium, showing conspicuous septa in 

 fertile branches, and relation of latter to axial filaments: a, b, c, branches 

 proliferated successively from same filament; bi-bj, ci-cj, elements prolif- 

 erated successively from branches b and c respectively. 



Fig. 7. — Portion of branch c (fig. 5) showing attachment of successively 

 formed spiral elements. 



Fig. 8a-/. — Successive stages in development of fertile hypha. 



Actinomyces III 



Figs. 9-14. — Portions of aerial mycelium. 



Fig. 15. — Portion of degenerate hypha containing abundance of meta- 

 chromatic material. 



PLATE III 



Actinomyces IV 



Fig. 16. — Short chain of spores showing nuclei, and 2 deep staining 

 remnants of constricted septa in hyaline isthmuses between spores. 

 Figs. 17-20. — Portions of aerial mycelium. 

 Fig. 28. — Spore germinating with 2 germ tubes. 



