- th) Bacterial Flora of the Atlante. 391 
: = of the very fine blue and gray silt yielded on the average 
J tout 17,000 germs per cc. Thirty-five samples of a mixed 
_uartz sand and clay gave an average of nearly 20,000 germs 
frunit of measure. The few samples of pure shifting sand 
‘Were practically free from organic matter and contained only 
“Mout 5,000 germs. Not enough tests were made to say 
whether this ratio would be maintained or not, but the dif- 
‘tence between the sandy clay and silt is quite within the 
limits of ordinary variation. The species found in the pure 
‘fd did not differ from those growing in the clay soils. 
. Quantitatively, the marine mud in the vicinity of Woods 
contains much less germ life than that of the Mediter- 
-‘fahean in the vicinity of Naples. The Naples cultures made 
fom mud taken at the depth of 150% or less, yielded 
‘Sully from 200-300, 000 germs per cc., while those made 
M this side of the Atlantic in only exceptional instances ex- 
~ $9,000 germs while the average content was about 
140,000 per unit of volume. Just what conditions bring 
- Bout such a 
: are able to live. At all events, the conditions 
‘ty af + are in all probability more nearly. normal sper 
ch enorm aples, as the possibility of the introduction 0 
Mein thi ous numbers as would be derived from a large city 
= tase excluded. 
on's work has been carried on in much more 
Period se but the difference in temperature is not ee 
the te Observation at Naples extended from Apri : oO 
60°_ oP “ature of the water during this time varying 
ater bea ls y ear the work was carried on some: 
June-August), the temperature ranging from 55 - 
| This Seas, 
€ is one of the more important factors that 
ion of micro-organisms, but it would ae 
at the difference in bacterial contents of the 
