224 Wisconsin Academy of Sciences, Arts, and Letters. 
A moderate number of colonies of diplococci was always found. 
The individual cells varied in diameter from 0.5 to 0.8 microns 
but were usually about 0.6 microns. 
A few streptococci and a few staphylococci were found also. 
Nearly as many colonies of small rods was found as diplococci. 
These colonies had dense centers and open edges where the individ¬ 
uals were grouped in pairs with a slight tendency to form short 
chains. The cells varied in width from 0.5 to 0.7 microns with 
a few as wide as 1.0 micron. In length they ranged from 1.0 to 
3.5 microns, averaging about 2.0. 
Several of the guinea pigs showed large rods which were ar¬ 
ranged in extremely long chains. These lay parallel or interlacing 
and most generally radiating from the dense center of the colony. 
About one-third of these animals showed the presence of smaller 
rods which grew into shorter chains than the foregoing. 
Spores were quite abundant. 
The dejecta of several scurvy guinea pigs was examined. The 
bacteria varied little here from those found in the normal animals. 
Except that the types were fewer and the colonies larger and 
more compact than usual. 
By comparison with little plates of pure cultures the following 
species were recognized: Staph.alhus{^), Strep.lacticus, B.coli, 
and B.subtilis. See figs. 9,10, and 17. 
Puppies. The fecal bacteria of the three puppies studied con¬ 
sisted of many diplococcus colonies, a moderate number of strep¬ 
tococcus colonies and a few staphylococcus colonies. Many large 
bacillus colonies and a few colonies of very short bacilli. 
Rats. There were many colonies of diplococci, streptococci 
and staphylococci. Also many large bacilli of which some were ar¬ 
ranged in spreading interlacing threads and others isolated or in 
pairs. 
Some of the colonies were Gram positive and spore bearing and 
others Gram negative and non-sporulating. 
The organisms found are believed to be: Staph.alhusi^l), 
Strep.lacticus, B.acidophilus, B.hifidus, B.mesentericus. See figs. 
4, 5, 7, 8, 14, 18, 20, and 21. 
Photomicrographs of some of the most frequently encountered colonies 
are given in the accompanying plate (No. IX). 
Colonies from the stools of infants are reproduced in figures 1, 2, 3, 6, 11, 
12, 13, 15, 16, and 19. Those from guinea pigs in 9, 10, and 17; and from 
rats in 4, 5, 7, 8, 14, 18, 20, and 21. 
