DESORIPTIO^Sr OF PLATES XV. AND XVI. 

 Actinomyces. 



PLATE XV. 



Fig. 1. — FTom a preparation of the grains from an actinomycotic abscess in 

 a. boy ; examined in glycerine. The drawing has been made of a com- 

 plete rosette examined by focussing successively the central and peripheral 

 portions. Towards the centre the extremities of the clubs are alone 

 visible ; they vary in size, and if pressed upon by the cover-glass give the 

 appearance of an irregular mosaic. Towards the periphery the clubs are 

 seen in profile, and their characteristic form recognised. At one part 

 there are several elongated elements, composed of separate links, x 1200. 

 Fia. 2. — Different forms of clubs from preparations in which the rosettes have 

 been flattened out by gentle pressure on the cover-glass, x 2500. 



{a) Single club, (b) Bifid club, (c) -Club giving rise to four 

 secondary clubs. ((?) Four clubs connected together, recalling 

 the form of a bunch of bananas, (e) Mature club with a lateral 

 bud. (/) Apparently a further development of the condition 

 represented at (e). (g) Club with a lateral bud and transverse 

 segmentation. (A) Single club with double tranverse segmenta- 

 tion, (i) Club with oblique segmentation, (j) Collection of 

 four clubs, one with lateral gemmation, another with oblique 

 segmentation. (_A) Club with lateral buds on both sides, and 

 cut oS square at the extremity. (I) Club with a daughter club 

 which bears at its extremity two still smaller clubs, (m) Club 

 divided by transverse segmentation into four distinct elements. 

 (n) Elongated club composed of several distinct elements, (o) and 

 (p) Clubs with terminal gemmation, (g') Palmate group of clubs, 

 (r) Trilpbed club, (s) Club with apparently a central channel. 

 (t) Filament bearing terminally a highly refractiveoval body. 



PLATE XVL 



Fig. 1. — From a section of a portion of the growth removed from a boy 

 during life. The tissue was hardened in alcohol, and cut in celloidin. 

 The section was stained by Gram's method and with orange-rubin. x 50. 



Fig. 2. — From the same section. A mass of extremely fine filaments occupies 

 the central part of the rosette. Many of the filaments have a terminal 

 enlargement. The marginal part shows a palisade of clubs stained by the 

 orange-rubin. x 500. 



Figs. 3 and 4. — From cover-glass preparations of the fungus teased out of the 

 new growths produced by inoculation of a calf with pus from a boy 

 suffering from pulmonary actinomycosis. Stained by Gram's method and 

 orange-rubin. The threads are stained blue and the clubs crimson (a) 

 In the younger clubs the thread can be traced into the interior of the 

 club (b). In some of the older clubs the central portion takes a yellowish 

 stain, and in others the protoplasm is not continued as a thread, but is 

 collected into a spherical or ovoid or pear-shaped mass. In others, again 

 irregular grains stained blue are scattered throughout the central portion 

 (Fig. 4). X 1200. 



Fig. 5. From a pure-culture on glycerine-agar. (a) branching filaments, (J) a 

 mass of entangled filaments. Gram's method, x 1200. 



Fig. 6. — From a similar but older cultivation, (a) a filament with spores 

 (b) chains of spore's simulating streptococci. Gram's method, x 1200. 



