1919] DRECHSLER— ACTINOMYCES 73 



conditions, of forms like the smuts, Mucor, and Penicillium, would 

 make advisable a larger measure of caution in dealing with fungi 

 growing irregularly in a submerged condition. 



Although various details associated with the sporulation of 

 Actinomyces have thus been dealt with in the literature, the opinion 

 still seems to prevail widely that the process is of an irregular and 

 miscellaneous nature. Litman and Cunningham (14) in recent 

 years have denied the character of spores to the "gonidia" pro- 

 duced by the potato-scab organism; the elements are believed 

 simply to "serve as a segment of the mycelium, which, by increasing 

 the number of segments, may increase the chances for spread and 

 continuous existence." This view seems, in the opinion of the 

 writer, very much at variance with the distinctiveness of the well 

 characterized sporogenous apparatus found in Actinomyces. 



In pursuing the present studies a method of mounting material 

 was employed which, in view of the exceptional fragility of all 

 species of Actinomyces, and the great difficulty ordinarily en- 

 countered in attempting to stain undisturbed sporulating condi- 

 tions, gave exceptionally good results. The plants were grown on 

 a suitable substratum, usually potato or glucose agar. Growth on 

 potato agar, as a general rule, is more. prompt and productive of 

 mycelium; but as its use, especially with species exerting a strong 

 tyrosinase reaction, stimulates to excessive guttation and dis- 

 ruption of the sporophores by the extruded droplets, a medium not 

 possessing this property is often found to be advantageous. After 

 the cultures had attained a proper degree of maturity, the whole 

 growth was cut from the agar and removed from the tube as care- 

 fully as possible. A slide smeared with albumen fixative was now 

 brought into firm contact with the mycelium and then separated 

 from it, precautions being taken to avoid altogether any sliding of 

 the two surfaces on each other. If the growth is not too young, 

 this procedure will leave the upper portions of the aerial mycelium 

 adhering to the shde without serious disarrangement, and killing 

 and fixation may be at once effected by the use, for example, of 

 strong alcohol. The material was subsequently stained and 

 mounted in balsam. The quality of preparations in which the 

 spore chains have commenced to disintegrate in large numbers is 



