the shoots project above its surface. Then they are taken from 

 these pans, one by one, and fixed in the prepared cork stoppers. 

 They should not be placed in distilled water or tap water at all, 

 but are thus kept in the germination solution until they are 

 actually placed in the culture jars. Have the hands clean ; 

 paraffined forceps are useful. 



2. Seedling Phase. 



Culture Jars and Corks, and the Setting Up of Cultures. The 

 culture jars used for the seedling phase are to be ordinarily glass 

 fruit jars, of the "Mason" type, the quart size. It is essential 

 only that the capacity be approximately correct and that the 

 opening be suitable for the corks carrying the seedlings. One 

 distinct advantage of the "Mason" jar is that it is supplied in 

 three sizes (pint, quart and two-quart) , all with the same size of 

 opening; another advantage is that this jar is procurable prac- 

 tically everywhere in the United States, and at a low price. 

 The tops supplied with the jars are not needed in this work. 



Each jar is to be covered by a cylindrical jacket of opaque 

 paper, white on the outside, to keep strong light from reaching 

 the roots of the plants. It is desirable that the jacket be so 

 arranged that it can be readily removed without disturbing the 

 plants (for examination of the root systems, etc.). A good 

 method is that employed by Shive (1915) . A jacket that is dark- 

 colored on the outside is not suitable, since absorption of radiant 

 energy is undesirable. 



The corks used for closing the jars and for supporting the 

 seedlings should be of good quality, of the flat form, one-half 

 inch thick and of a diameter to fit the opening of the jar used. 

 They are to be thoroughly impregnated and thinly coated with 

 paraflfin, such as "Parawax." A very excellent arrangement for 

 mounting the seedlings is that adopted by Tottingham (1914). 

 Only five seedlings per jar will be used in the present coopera- 

 tion. It is strongly urged that this arrangement be employed, 

 for the sake of uniformity, but if another arrangement is used it 

 should conform in the essentials. Those essentials are : that the 

 five seedlings must be firmly held just above the seed in each 

 case, with but slight pressure opposed to subsequent increase in 

 the stem diameter in this region; that the jar be practically 

 closed; that the stopper be protected from fungi; and that the 

 technique of placing the seedlings be simple (so as to be rapid 

 and to avoid undue disturbance of the delicate plantlets during 

 the process of placing) . Ready-prepared corks may be obtained 



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