290 Ethel McLennan : 



October 13tli. — I'he nitrogen-free seedlings were very un- 

 healthy. The second leaves showed discolouration, and 

 were dying from the tip downwards. Very much behind 

 the control. 

 October 20th. — The nitrogen-free seedlings were beginning to- 

 die out. I he control seedlings were exceedingly 

 vigorous and normal. 

 October 30th. — The experiment was dismantled for photo- 

 graphic purposes, as the remaining nitrogen-free seed- 

 lings were failing rapidly. 

 The phenomena noted during the course of the experiment are- 

 typically those resulting from nitrogen starvation. The yellowing" 

 of the older leaves always commencing at the tip indicates that these 

 members are being sacrificed in order that any nitrogen they pos- 

 sess (i.e., nitrogen obtained from the seed) may be made available 

 for transference to the young developing leaves. This transference 

 of nitrogen from the first-formed leaves to the actively growing 

 centre enables the plant to exist for a certain period of time, but 

 the lack of nitrogen manifests itself in the stunted growth and 

 unhealthy colour and appearance of the plants. 



It may be concluded from this experiment that no power of 

 nitrogen-fixation in the absence of external supplies of combined 

 nitrogen can be ascribed tO' the endophytic fungus of Lolium 

 perenne. 



Conclusion. 



It is difficult to decide what is the actual relationship between 

 the fungus and the Lolium plant. It could, perhaps, be regarded 

 as a case of symbiosis, the fungus helping in the plant economy 

 during the formation of the grain. In return for this it is housed 

 by the grass, and its propagation is ensured by the admittauco of 

 hyphae to the embryo, so that it is able to appear in each successive 

 generation without the intervention of a spore stage. It can only 

 be a matter of conjecture whether this stage is entirely lost to the 

 fungus or whether it is repressed, only as long as conditions are 

 favourable to its transmission in the usual way, but still retains 

 the power of sporing if in danger of extermination. Ihe sporing 

 stage may occur under such conditions, but up to the present it 

 has not been recognised as belonging to the fungus normally 

 found associated with at least two species of Lolium. 



As opposed to this conjecture. Freeman (26), although he had not 

 demonstrated the intra-cellular nature of the fungus, advocated 



