1896.] MICROSCOPICAL JOURNAL. 375 



obvious that the mere presence of even these in the nor- 

 mal conjunctiva does no harm. A bouillon culture of 

 the staphylococcus aureus has been dropped into the 

 conjunctival sac of man without producing inflammation 

 (Bach), and even in injured eyes these bacteria often 

 seem to do no harm, as ma}' be seen from some later ex- 

 periments in which the staphylococcus aureus v^as found 

 in considerable numbers in the dressings of eyes which 

 had been operated on for cataract and yet no suppura- 

 tion occurred after the operation. But in spite of these 

 facts it is well to remember that a purulent infiltration 

 of the cornea and panophthalmitis result when the staphy- 

 lococcus aureus is inoculated upon the surface of the 

 cornea of a rabbit with an instrument infected with the 

 staphylococcus aureus, panophthalmitis develops in 

 thirty hours. The same result occurs also at the end of 

 seventy-two hours even with the staphylococcus albus. 

 Moreover, in man the staphylococus aureus and albus 

 seem to play an important part in many disastrous pro- 

 cesses occurring in the eye. Thus, the aureus seems to be 

 a very important if not the sole factor in many cases 

 of panophthalmitis and phlyctenular conjunctivitis. 



These two series of facts illustrating the harmfulness 

 and harmlessness of the staphylococcus aureus and albus 

 can be harmonized only by referring them to a varying 

 vitality of tissues in different patients or to a varying 

 virulence of the bacteria. 



Next an attempt was made to determine whether age 

 influenced the kind and number of bacteria in the con- 

 junctiva. For this purpose the eyes of twenty old peo- 

 ple, ten childern, and forty-six young adults were ex- 

 amined. Thirty-three per cent of the tubes from young 

 adults were sterile; thirty per cent of the tubes from 

 old people were sterile; fifty per cent of the tubes 

 from childern were sterile. The percentage of sterile 

 tubes from adults and old people was about the same 



