THE CROWN GALL: TECHNIC 451 



not in flower-bud or in blossom. They should be set into 

 shallow boxes in sand in close rows, and the foliage trimmed 

 up considerably. Here they should remain for about 3 weeks, 

 i.e., until a callus has formed and roots begin to push. Bottom 

 heat is not necessary, as they root readily. They should 

 then be put into good soil in thumb pots and transferred from 

 time to time (rather frequently) to larger pots so as to keep 

 them growing rapidly. There should be no check whatever 

 in their growth else they will bloom prematurely. Pelargonium 

 slips should be treated in the same way. Peaches and almonds 

 should be planted in similar boxes of sand after carefully cracking 

 and removing the shell, without injury to the kernel. Hard- 

 shell almonds as they come upon our markets are more likely 

 to germinate than the bleached thin-shell almonds. Two or 

 three months must be allowed for growth. Ricinus, tomatoes, 

 tobacco, sunflowers, sugar-beets, and turnips should be grown 

 from seed. Allow at least 2 months. Cuttings of willows and 

 poplars may be rooted in the spring for use in houses the follow- 

 ing winter or spring. 



Determine 



FOR THE ORGANISM. Morphology. In various media, size 

 in microns; form; aggregation of elements, i.e., chains, filaments, 

 pseudozooglceae; motility, presence and distribution of flagella 

 (use Pitfield's stain); absence of endospores; capsule stain; 

 Gram's stain; acid-fast stain; character of the involution 

 forms. 



Cultural Characters. Size and appearance of colonies on 

 thin-sown agar and gelatin plates; stabs and streaks on agar; 

 ditto on gelatin; behavior in peptone bouillon (watch early 



FIG. 343. Hard crown-gall embryoma, on mango (Mdngifera indica). Ter- 

 minal bud inoculated by the writer January 19, 1916, by needle pricks using the 

 hop strain of Bacterium tumefaciens (sunflower Colony 1). This tumor contains 

 6 distinct centers of embryonic growth. For one of the larger ones (under the 

 arrow) see Fig. 344A. Surface brown except the embryonic parts which were green. 

 The leaves surrounded by the tumor, and appearing to grow out of it, are 

 stem leaves. Time, 20 months (nearly). Photographed by James F. Brewer, 

 September 11, 1917. % nat. size. Actual size of the tumor 6) by 4^-j by 4 

 inches. 



