Crosfi Inocublatiun of the Root Tubercle Bacteria. 196 



Method of Attuvkii(y the I'nihltin. — Eight ul' the luure important 

 iiieuibt'r.s of the Leguminosat.' weit' taken, viz. : — 



1. Bioad Beau Vicia Fabu. 



'J. Kidney Bean J*haseolus vulgaris. 



.'!. Field Pea Pisuni sativuni. 



4. Soy Bean Glycine hispida. 



.J. Lucerne Medica<:u sativa. 



8. 



JMack .Medi.k 

 FJed rinvrr 

 Ilaiiv \"et(li 



iM.r 

 rli(t.sen 



cros.s inoculatidii l»ur]Kl^^es. 



.Medic ago hipulina. 

 Trit'uli 11111 |>ratense. 

 \ icia villot<a. 

 the followintr 



plantn- 



were 



Miiuosae. 



\ Papillionaceae. 



I. Aiacia iiiolliMsiuia 



-. IMatyhil)iuni obtusanguluni 

 •!. Swainsona galegifolia ... 



4. Aotus villosa 



5. Bossiaea cinerea 



Arranyeinent of Serie-s of L'ot^. — According to Hiltner and 



Stornieri, if put exjjerinients were to be carried out, inoculation 

 by nodule contents was the best way; but fur held woxk, inoculation 

 Ijy ])ure cultures of the bacteria yielded the best results. Since i'. 

 vas only possible to keep everything sterile in pot experiments, the 

 eight diti'erent kinds of seeds were planted in pots, and each series 

 was inoculated by the bacteria from a different native legume, thus 

 giving hve series, a sixth being planted iiniaoculatetl. and ci'inpris- 

 ing a control, a total of -J.^ ])ot i>lants l)eing used for each exj>eri- 

 nient. 



.\s till' risk of coiitaminatiiui and outside infection must be com- 

 pletely overcome, everything l)efore use was thoroughly sterilised. 



Mf-fhod of Sterilisation and l'neo>ifion.<. — The pots l)ef<jre sow- 

 ing were placed in the steamer and kci)t at boiling ]Miint for 2 

 huui's. '2 days later being resubjected to the same treatment; this 

 would effectively get rid of any foreign ro(tt tubercle bacteria that 

 might be present. The seeds were well washed for a few minutes in 

 a 2 per cent, solution of formaldehyde, and then several times in 

 boiled water. This treatment seemed effective enough, yit Harriso/i 

 and Barlow- ({'anadian investigators) say (hat the vnrioii- uietluids 

 of sterilisation arc of no avail in removing the living bacteria from 

 the living seeds; and. in fact, in two cases with clover plants 

 nodules appeared who.se origin was difficult to explain except on the 



1 L. Ililtner atid K. Sioinier. Berlin. .\i-l). l)io1. .\btli. Gesundhtsamt. ;5. 19ii3 (l.-)l-.^07, 44?-545). 



2 F. C. Harrison and 15. B.irlow. The nodule orsanisni of the Lestuminosac its isolation and 

 cultivation, identifii-ation ;md commercial application. (Psendomona-* radicicoIa>. Canada, I'Mt'. 



