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Mr. E. M. Freeman. 



[June 6, 



infection of the plant, although the presence of hyphse in the growing 

 point from about the 8th day of germination to the formation of the 

 fruit had been observed by one investigator, and but little positive 

 evidence as to the real nature of the fungus has been produced. 



In addition to the now known hyphal layer outside the aleurone of 

 the grain the author has discovered a hitherto unnoticed patch of 

 hyphse, just outside of and contiguous to the base of the scutellum. 

 From this patch hyphse can be found penetrating to the growing point 

 of the embryo in the seed, and an abundant mycelium can usually be 

 detected in the young growing point. The hyphse continue their 

 growth, always intercellular, in the growing point and in the leaf-bases 

 until the formation of the inflorescence, when every young ovule con- 

 tains an abundance of hyphse throughout the nucellus, and extending to 

 within two cells of its exterior. When the ovule elongates and assumes 

 the ovoid form, there is formed a tongue of hyphse extending in the nu- 

 cellus, from the funicular side to the micropyle on the inner or axial side 

 of the embryo-sac. This patch becomes isolated by the further elonga- 

 tion of the ovule, and by the cessation of growth of the hyphse in the 

 funicle, and remains vigorous, forming an infection layer. When the 

 embryo has attained a length of about 3/10 mm. and the rudiments 

 of a lateral growing point and a terminal scutellum have been formed, 

 the hyphse penetrate from the infection layer into the growing point, 

 and can be found here in abundance in the mature grain. 



No trace of any formation of spores can be found anywhere, and 

 they seem therefore unnecessary for the ordinary life-cycle of the 

 fungus. The bulk of the nucellar hyphse of the ovule are crowded 

 into the layer occupying the now well-known position in the grain, by 

 the growth of the endosperm. They sometimes penetrate the latter, 

 but have never been seen to form either sclerotia or spores. This 

 layer disintegrates during the germination of the grain. 



Other varieties or species of Lolium also contain such a hyphal layer 

 occasionally, probably identical with that of Darnel. I- have found it 

 in L. temulentum, var. arvense, With., and^i. linicola, Br., very abund- 

 antly, and rarely inL. perenne, L., L. multiflorum,, Lam., and Z. italicum, 

 Br., besides in several doubtful species. Several facts — prominent 

 among which are the ordinary sterility of the fungus and the apparent 

 stimulation of the Darnel plant, as shown in the germination efficiency 

 and the large size of the grains — point strongly to this being a 

 remarkable instance of symbiosis. Such a symbiosis can be conceived 

 as derived through a sclerotial or spore-forming condition by the sub- 

 stitution of an intra-seminal infection of the embryo after failure to 

 reproduce in the usual way. 



The principal points dealt with in the full paper, which is illustrated 

 by figures, may be shortly summarised as follows : — 



