No. 608] SHORTER ARTICLES AND DISCUSSION 



505 



the alluvial fans at the mouths of both the Bear and the Jordan 



The results seem to indicate that the diatoms obtained are true 

 Salt Lake forms, but have become adapted to less severe condi- 

 tions than prevail in the denser waters. That they are not fresh- 

 water forms which have accidentally found their way into the 

 lake, is suggested by the fact that they do not thrive in the least 

 dense of the solutions of any of the series. 



In every series, a cloudiness in the solution appeared as a re- 

 sult of bacterial growth, but the order of appearance in every 

 ease was from the least dense solutions up to the most dense. 

 This cloudiness soon disappeared, to reappear at irregular in- 

 tervals. These facts led to an attempt to determine at least the 

 number of species of bacteria which may be found in the part of 

 the lake studied. So far as we can determine, no attention what- 

 ever has been given this phase of the question in the past. 



Five distinct organisms, which have adapted themselves to 

 conditions there, were isolated in pure cultures. No detailed 

 study was made of them to determine their species, but enough 

 was done to leave no doubt as to their being at least separate 

 varieties, if one may judge from distinct differences in cultural 

 and morphological characteristics. 



"Watt'r obtained fcoiii tho lake uiidor tlio strii-ti'st precautions, 



sists of 40 (■('. of iioriiial sodiuin liydfoxidc and grams sodium 

 chloride, to 1.000 cc. of plain agar. Later samples of the water 

 were plated on gelatins containing different amovnits of the 

 normal NaOII, and NaCl. Better results were obtained with 

 the salt agar than with the gelatin. Later, plain agar was used 

 with good results. 



• of samples taken in the 

 ,s in the warmer weather. 



organisms isolated, three arr decid.'d diromogens, each produc- 

 ing aliuiidaiit pigment. Of tlir five, one is a diplococcus, which 

 appears sometimes in tetrads and singly. It forms large white 

 colonies on tlie media used. The other four are bacilli. The 

 6ne producing no pigment, forms delicate white colonies on the 

 solid media. Of the chromogens, one produces a lemon-yellow; 

 a second produces a bright orange; and the third produces a 

 violet pigment. 



