284 



Ethel McLennan : 



Ilie following figures are extracted from his paper 

 I. — Without 7iitroge7i manure. 



Nitrogen 





Dry Weight 



absolute mg. 



per cent. 



Lolium temulentum - 



5.173 



30.35 



0.59 



Lolium italicum 



0.974 



6.69 



0.69 



Root mixture 



3.619 



7.78 



0.22 



Total - 



9.766or. - 



44.82mg - 



0.46% 



II. — Manured with 50 mg. of nitrogen. 



Nitrogen 





Dry Weight 



absohite nig. 



per cent. 



Lolium temulentum - 



5.867 



72.87 



1.24 



Lolium italicum 



2.329 



40.70 



1.75 



Root mixture 



3.381 



12.60 



0.37 



Total - 



- ll.o77ffr. 



- 126.l7m^. - 



1.09% 



The nitrogen content of Lolimn temulentum plants, when fer- 

 tilised w4th potassium nitrate, is seen by the above figures to in- 

 crease markedly as compared with that obtained for unfertilised' 

 plants, i.e., plants watered with tap water only. Net only is this 

 so, but the increase is nearly as great as that obtained for Lolium 

 italicum. The small difference between the percentage results for 

 both species is not outside the limit of experimental error, especi- 

 ally when the sources of such error are as great as in the experi- 

 ment in question. 



Kayner (20) when dealing with the symbiotic relation of an asso- 

 ciated fungus in Calhma vulgarii^, refers to the case of Darnel 

 grass, and says : " Some degree of symbiosis has been inferred, but 

 the experiments of Hiltner to establish nitrogen fixation for this 

 fungus are inconclusive." 



In describing the distribution of the fungus (a peculiar mycor- 

 rhizal form) found in Calluna vulgaris,, Rayner draws attention to- 

 the fact that in many points it resembles the fungus in Darnel. 

 The fungus from Calluna was isolated and grown in pure culture, 

 and was found to be closely related to the genu? Phoma ; nitrogen- 

 fixation was suggested as its function. Duggar and Davis (21) 

 showed that Phoma Betae, when grown on mangel or sugar beet 

 decoction, produced a nitrogen gain of from 3.022 — 7.752 mg., 

 pointing definitely to nitrogen fixation for this particular fungal' 

 species. In fact, it w^as the only definite positive result obtained 

 from all the forms experimented with. 



