460 HIGHER FISSION-FUNGI. 



(b) Magnified fifty times. Superficial colonies: The center 

 is opaque, brownish-yellow, passing gradually into a yel- 

 lowish-gray peripheral zone which consists of very closely 

 set, fine, radiating hairs (69, vi). Deep colonies : Roundish, 

 nodular, yellowish-brown, here and there presenting single 

 or bunched projecting hairs (69, vn). 



Agar Stab. — Surface growth : Yellowish-gray to brown, 

 rather smooth-bordered, slimy. Gradually it becomes dull, 

 with some whitish elevations. In the stab the growth is 

 like a grayish-white thread. After several months the 

 agar becomes colored dark brown (69, in and iv). 



Agar Streak. — Like the surface growth of the stab cul- 

 ture. Upon the water of condensation is a tough, wrinkled, 

 brownish pellicle. Where this passes on to the tube-wall 

 it is pure white. The water of condensation is clear 

 (69, ii). 



Bouillon Culture. — Only on the surface there is a 

 tough, thick, wrinkled pellicle, which is firmly adherent 

 to the glass. 



Milk Culture. — On the surface a dense scum. The 

 milk is not coagulated, and while the milk becomes trans- 

 parent, a limited white precipitate is formed. 



Potato Culture. — There is rapidly formed an elevated, 

 reddish to grayish-brown, sharply outlined growth. In 

 time the surface develops wavy wrinkles. In old cultures 

 the peripheral zone presents a white, chalky discoloration 

 (69, x). 



Spores. — There are no endospores. 



Distribution. — Found by Bizozzero upon the skin of 

 healthy men. 



Related Varieties. — This variety resembles in many 

 points the subtilis-mesentericus group. Wavy growth, 

 vigorous liquefaction, and air hyphae upon potato are 

 observed, in which respects its cultures are very similar to 

 those of the B. subtilis. The variety is more properly 

 called Bacillus epidermidis. To be sure, it must then be 

 taken for granted that accidentally a spore-free form of 

 bacillus is exemplified in this variety. 



