THE NOEMAL CONJUNCTIVA 39 



The organisms described in our literature as Micrococcus Jlavus 

 desidens (Burchardt, Bach, Basso, Wilbrand, Siinger, Stahlin) and 

 Micrococcus subftavus (Wilbrand, Sanger, Stahlin) are characterized 

 by very slight pathogenicity, and the absence of liquefaction in 

 gelatine. The Staphylococcus cereus flavus (Bach, Lachowicz, Basso), 

 so called by Passet on account of its dull, wax-like appearance, does 

 not liquefy gelatine, is only feebly pyogenic, and is closely related to the 

 above-named yellow cocci. In the latest literature this variety is 

 no longer noted. 



The Micrococcus sulphureus of Zimmermann, which Lehmann and 

 Neumann considered as a non-liquefying form of their Micrococcus 

 flavus, is a lemon-yellow coccus, of which I have several times obtained 

 specimens. It does not liquefy gelatine, and only produces a slight 

 inflammatory reaction in the cornea. Many cultures of this variety 

 grow very slowly, and correspond to the Micrococcus sulphureus 

 tardigradus (Fliigge), which Lehmann and Neumann considered as 

 merely a variety of the former. The Micrococcus citreus (Basso) of the 

 conjunctiva is identical with this organism, and the Diplococcus citreus 

 conglomerate of Bernheim, Bach, and Basso is closely related. 



Passet's form of the Staphylococcus pyogenes citreus, which liquefies 

 gelatine like the aureus, and produces a free suppuration in the rabbit's 

 cornea, is much rarer. I have only found it twice in scattered 

 colonies. It is not possible to determine from the scanty details given 

 whether the Staphylococcus citreus described by Pollock was pyogenic 

 or not. 



The Sarcinse (especially Sarcina lutea, aurantiaca, flava, alba) occur- 

 ring in the conjunctiva not infrequently, though mostly in isolated 

 colonies, are related to the non-pathogenic cocci to this extent, that they 

 can appear in the secretion as Diplococci or Tetracocci. Very possibly 

 the large Diplococci, which are sometimes met with in the secretions 

 from chronic conjunctivitis, and which, when faintly stained, can be dif- 

 ferentiated as Tetrads, are really Sarcince. Although in the course of 

 years I have often seen colonies of Sarcince in cultures, and have always 

 compared the smear preparation with the culture, I cannot remember 

 having seen a definite packet form in the conjunctival secretion, and 

 if such did occur in a fluid it would be very easily recognized. Tetrads, 

 too, have very often a peculiar grouping. 



Migula, Stubenrath, Lehmann, and Neumann, have bridged over the 

 line of separation between Sarcina and Micrococci. These investi- 

 gators succeeded, on suitable media, especially hay-infusion, in growing 

 Sarcince forms of many Micrococci. In this manner Migula produced 



