588 BACTERIA IN INFECTIOUS DISEASES. 



and scalloped. At this time it covers about two-thirds of the surface of a 

 potato stick half an inch in diameter. After the first week the growth is 

 slow, and at the age of three weeks its size only equals that of the iirst week, 

 but the colony itself is shrivelled, dried, and dark in color. In milk the cul- 

 ture had on the second day a slight greenish tinge, which, by the fifth day. 

 had disappeared. The upper quarter inch of the milk seems slightly thicker, 

 but no other change is visible to the naked eye. 



" Variety 2. In. appearance it is almost identical with Variety 1, except 

 that it seems more oval in form. This diplococcus is aerobic, non-liquefy- 

 ing, and chromogenic. As in Variety 1, the ordinary changes of tempera- 

 ture, as occur from the rotation of the seasons of the year, retard or acceler- 

 ate the growth of the culture. On Petri dishes of gelatin, the minute, 

 round, yellow colonies appear on the third or the fourth day. Those on the 

 surface grow slowly, are slightly raised, and have smooth borders. After 

 the first week's growth the centre shows a deeper orange color. On agar' 

 'agar, the growth is slightly lustrous, thicker, and of a light orange color. 

 On potato, a deep golden layer develops, which is well raised and has irreg- 

 ular borders. In milk, this diplococcus grows as Variety 1 does, except 

 that after ten days the upper layer of the milk is thickened and has turned 

 the same golden color mentioned. In stab cultures of Varieties 1, and 2 the 

 growth adheres pretty closely to the puncture line, gradually spreading 

 down it and over the surface. 



" Variety 3. A bacillus with rounded ends, single, in pairs, or in short 

 or long chains. It is aerobic and anaerobic, motile, liquefying, and non- 

 chromogenic. In gelatin tubes a grayish- white growth commences on the 

 second day. In smear cultures a pit of liquefied gelatin is formed, and, re- 

 maining of the same irregular shape as the smear, it gradually deepens and 

 contains at the bottom a whitish sediment. In stab cultures the resulting pit 

 is the shape of the puncture and contains the same white sediment. On aga r- 

 agar the growth is whitish, its surface raised, without lustre, and its border 

 indented. 



" Inoculation experiments were attempted in twelve cases. The site of 

 inoculation chosen was the hairy scalp, or over the sternum. After thor- 

 oughly sterilizing the skin, two or three hairs were pulled out and the skin 

 slightly abraded, as in vaccination ; portions of an actively growing culture 

 were then rubbed in with a sterilized platinum needle. With No. 3 two 

 attempts were made and both failed. With No. 1 five attempts were made. 

 Of these, one was a failure. In the four others the edges of the inoculation 

 spots began to grow slightly reddened from the fourth to the sixth day, and 

 small scales formed on the surface. By the seventh to the tenth day t lie 

 spots had increased in size and were covered with dry white scales. Scales 

 taken from these spots and placed in suitable culture media in each case gave 

 rise to pure cultures of diplococcus No. 1. Variety No. 2 was used ome. 

 On the sixth day yellowish scales appeared over the surface. They grew 

 slightly more marked on the tenth aay, and the lesion then closely resem- 

 bled certain typical forms of seborrhceic eczema. Diplococcus No. II. was 

 found in the cultivations from these scales. The last four inoculations were 

 made with both No. 1 and No. 2. Of these, one was a failure. Another 

 showed a small spot covered with a few branny scales, too small to allow of 

 any conclusions being drawn. In the other two achange began on the fourth 

 day. The bases began to redden, and typical, crumbly, greasy scales began 

 to cover the surfaces and pile up in the centres. On the eighth day the spots 

 were an eighth of an inch across, and represented patches of seborrhoeic 

 eczema. Both Nos. 1 and 2 could be cultivated from these scales. It is 

 possible that Variety No. 2 may have given the yellow color to those seal. -. 

 as it was absent in the successful cases 'using No. 1. 



"The result of the twelve inoculation experiments, therefore, are : Five 

 failures. Seven cases in which definite lesions were produced." 



