54 Sheppard : Quarizite Pebbles on the Yorkshire Wolds, 



The spores in the root hairs on germination gave rise to 

 a mycelium which produced the fusarium-Hke spores alluded to 

 above. This was repeatedly verified ; under certain conditions 

 the amount of myceline produced is very small, and the hyaline 

 spores are formed at a very short distance from the germinating- 

 brown spores. The hanging drop cultures were transferred to 

 Petri dishes containing sterilised bread, plum jelly, wood, orchid 

 pseudo-bulb, etc., and thus far only these two forms of spores 

 have been obtained. When first transferred to the new media, 

 growth takes place very rapidly and masses of the hyaline 

 spores are produced. After a few weeks the round brown spores 

 begin to be formed ; the production of these latter varies 

 greatly with the media on which they are grown. No ascigerous 

 stage has yet been found, but it is hoped that the conditions 

 required for the production of the same will soon be known. 



Other observers have described similar fungi from the roots 

 of different orchids. Wahrlich (Bot. Zeit., 1886) obtained from 

 two species of Vanda a fungus very similar in appearance to 

 that found in Eria ; but though the conidial stages of the fungus 

 found in the two species of Vanda were very similar, the 

 ascigerous stage differed sufficiently from one another for him 

 to regard them as different species. Chodat and Lendner (Rev. 

 Mycol, 1898) also described the mycorhizal fungus of Listera 

 cordata as resembling that of Vanda. 



QUARTZITE PEBBLES ON THE YORKSHIRE WOLDS. 



T. SHEPPARD, F.G.S., 

 Hull. 



Whilst assisting through the press Mr. J. R. Mortimer's forth- 

 coming work on ' Forty Years' Researches amongst the British 

 and Anglo-Saxon Burial-mounds of East Yorkshire, ' many items 

 have come under my notice which may be of interest in connection 

 with Mr." Stather's paper.* In the first place, it should be borne 

 in mind that the Britons almost invariably chose some prominent 

 point for the erection of their barrows, advantage being taken 

 of any slight rise on the surface. Mr. Mortimer frequentl\- 

 records the fact that barrows have been erected upon large 

 circular pipes of sand which penetrate the chalk for some distance. 

 This sand is usually of a ferruginous nature and exceedingly 



See ' Naturalist,' January, p. 9. 



Naturalist, 



