93 



and very feebly alkaline. It is made up of small roundish zo«^la^?e, short chains 

 of a dozen or more segments, and slender short rcnis, single, in pairs, or fours. Some 

 of ihe ro«ls are actively motile. 



Sixty-sixth day. 



{I) Chtck. — Slime strongly alkaline t<> neutral litmus. 



(2) Grapt' siujar. — wSlime not alkaline. Distinctly acid on nt-utral litnuis pajier. 



(3) Cane mgar. — No alkaline reaction. Slime distinctly aci<l on neutral litmus 

 paper. 



TWENTY-THKEE PER CENT SLGAKS.^ 



These cultures were like the preceding except that for each 1< » c. c. 

 of acrar ?> f^rams of the specitied sugar was used. The check tubes 

 had heen slanted longer than the others and their surface was drier. 

 All were smeared with Ps. hyaclnthi from an agar culture 24 days old 

 in the same way and with approximately the same amount of material. 

 The alkaline fruit-sugar agars already described were inoculated at the 

 .same time and from this same culture, which was the check tube 

 described under the 17 per cent sugar agars. 



Seventh, day. 



(1) Chivk. — A thin distinctly yellow growth over nearly the whole slant. 



(2) Grape sugar {S grams Merck's c. p. anhydrous) . — Xo growth. 



(3) Cane sugar [S grams white commercial). — A very feeble, scrappy growth, not 

 forming a streak, but confined to the immediate vicinity of some small fragments of 

 slime, which were left unspread when the agar was inoculateii. Xot more than two 

 or three times as much slime present as was put into the tul3e in making the inocu- 

 lation. Twenty-three per cent cane-sugar agar strongly retards growth. 



Twelfth day. 



(1) Check. — Fully twice as much growth as on the cane-sugar agar. 



(2) Grajx' s>ig<ir. — No growth, although the surface of the entire slant was rubbed 

 with a mass of yellow slime as large as a pin head. 



(3) Cone sugar. — A distinct, rather thin, wet, yellow, rough-surfaced growth, which 

 covers about one-half of the sUmt (lower half). 



Thirtieth day. 



( 1) Check. — Surface of the streak smooth, wet-shining, and distinctly yellow: no 

 reticulations or shagreen. 



(2) Grape sugar. — Xo growth. Ps. huacinthi will not grow on 23 per cent grape- 

 sugar agar. 



(3) Cane sugar. — The lower three-fourths of the slant is covered with a distinctly 

 yellow growth, which is rather dry, but looks wet mider the hand lens. The surface 

 is not smooth, but is reticulate, areolate, or shagreened, the portions between the 

 grooves l>eing lighter yellow and very smooth. This areolation is shown in Bulletin 

 26 of this Division, in text fig. 3, which was made from this culture on the thirty- 

 third day. The agar has not dried out much, but the slime shows no tendency to flow. 



'The expressions 9.17 and 23 per cent are useil for convenience. Of course, the 

 writer is aware that 3 grams added to 10 c. c. does not make exactly 23 per cent. 



