Leptothrix. 



35 



the white slime of the teeth, on the epithelium of the mouth, 

 and in hollow teeth ; probably 

 the cause of dental caries. 



The seat of this Fungus is espe- 

 cially in the canals of the dentine, 

 yet it also attacks the substance of 

 the enamel, which it destroys by 

 degrees. In those canals the Fungus 

 produces decided enlargements, and 

 afterwards their walls become pierced 

 by crevices and fissures, and break 

 to pieces. [According to recent 

 authors, the enamel must first be 

 attacked by the acids of the mouth, 

 before the Fungus can effect a lodg- 

 ment.] 



49. L. parasitica, Kiitz- 

 ing (Bot. Zeit., 1847, 

 p. 220). 



Threads very slender, for 

 the most part curled and 

 crisped, indistinctly jointed, 

 loosely felted, almost colour- 



Fig. 2ja. Leptothrix buccalis (after 

 Zopf). This is the form called 

 Zooglcea ramigera. 



less, about i p. thick, 100-140 p long. (Fig. 28.) 



Fig. 28. Leptothrix parasitica, X 600 (after Kutzing). 



Parasitic on Scytonemaceae and other allied Algae. 



Perhaps also Leptothrix pusilla, Rabenhorst, and L. Lanugo, Kiitzing, 

 should be placed among the Fungi. 



