Cultivation Association 591 



treated with alcohol or acids. Morax found that the bacilli 

 did not retain the color in Gram's method. 



Cultivation. The organism refuses to grow upon any of 

 the ordinary culture media. Weeks found, however, that if 

 the percentage of agar-agar used was reduced to 0.5 per 

 cent., growths could be secured by incubation at 37 C., and 

 successful transplantations carried on to the sixteenth gen- 

 eration. Abundant moisture was essential. The method 

 of isolation adopted by Weeks was as follows : 



"The conjunctival sacs were thoroughly washed with clean water, 

 removing the secretion present by means of absorbent cotton. The 

 patient was then directed to keep the eyes closed. After five or ten 

 minutes had elapsed, the eyes were opened, and the secretion that had 

 formed, lying at the bottom of the cul-de-sac, was removed by means 

 of a sterilized platinum rod and transferred to the surface of the agar. 

 The mass of tenacious secretion was drawn over the surface of the 

 organ and left there, the platinum being thrust into the agar two or 

 three times before removal." 



At the end of forty-eight hours a slight haziness appears 

 along the path of the wire, and on the surface of the agar 

 a very small patch is noticeable ; this is a pearly color and 

 possesses a glistening surface. By the formation of small 

 concentric colonies the growth extends for a short distance. 

 At the end of the fourth or fifth day the growth ceases to 

 advance; it is never abundant. The culture dies in from 

 one to three weeks. 



Pathogenesis. Both Weeks and Morax have tested the 

 organism for pathogenic activity, and in every case in which 

 pure cultures of it were placed upon the human conjunctiva, 

 typical attacks of the acute conjunctivitis resulted. The 

 organism fails to infect any of the lower animals. 



Association. Both Weeks and Morax found the organism 

 in intimate association with a larger club-shaped bacillus 

 which was regarded as the pseudo-diphtheria bacillus. It 

 seems to be of no pathogenic significance. 



