surfacjl sterilization. 



I (J' ) 



washed with equal cave in sterile distilled water. When many inoculations are 

 made with large niimbers of check plants and when due care has been taken to 

 work under conditions such that accidental contaminations from the same (organ- 

 isms are not to be feared, the writer has not found this precaution necessar)'. Tlie 

 use of mercuric chloride should he a\'oided, if possible, especialh' on lea\xs, as the 

 writer's experiments ha\'e shown that it penetrates into the jdant (sonre plantsj for 

 a considerable distance and prevents the acti(.)n of the l^acteria to this extent (fig. 

 88), if not altogether, as has happened in some cases. 



THK KKEl>IX(r OF KKCORHS. 



If one contemplates doing much work, a careful record of wliat has been done 

 is as important as the experiment itself, since exact remend)rance is certain to pass 

 awa}' with lapse of time. 



In all his work, the student should accust(jm liinrself to make \-er\' exact 

 statements, so that others ma}- be able to follow him. For example, he sliould 

 not describe his organism as ")'el]i_)w" or "red" witliout qualifications, since there 

 are man)- )-ellows and reds, but should carefully compare it with some standard 

 color-scale (Ridgwa}''s, Saccardo's, Standard I)icti(jnar\', etc.), and go\-ern himself 



accordingh-. He should not say, 

 " (Jrganism does not grow at 

 r(_>oni-temperatnres," but rather 

 shoidd state the temperature at 

 which growth does not (jccur, as 

 15°, 25", i>r 35° C, any one of 

 which ma\' be "room-temjiera- 

 ture,'' depending on the latitude 

 altitude, and time of }ear. He 

 should not sa^•, "Organism is 

 killed at temperature of ^^''C.," 

 without at the same time stating 

 the ao-e of the culture, condi- 



Flg. 94.* 



tions of exposure, and time required, which might l)e ten da^■s or five minutes. 



Every independent worker will in the end de\ise a method of note-taking which 

 is more or less characteristic of his personal peculiarities and l;cst adapted to his 

 owm particidar needs. For all persons there is no o/w hcsl method. The methods 

 described in the following paragraplis have been settled upon as those most con- 

 venient for the writer, but it does not follow that they are the most economical of 

 time, or the best de^•isable, or the ones wdiich independent workers should follow. 

 They are here gi\'en as hints for beginners and because the method a man emplows 

 in his work is ahva\s a matter of more or less interest to his fellow-workers. 



First of all, there should be pro\'ided a record book in wliicli the method of 

 preparation of each culture medium is carefulh' described. This should be a good- 



*Fic.. 94. — Hand-sprayer -which may he used for distributing haeteria on plants. Some form is 

 usually kept in every pharmacy and sold as a cologne atomizer. 



