382 Scientific Proceedings, Royal Dublin Society. 



It is more than likely that the disease described by Schoevers is identical 

 with that described by ns, and it is to be hoped that further research on the 

 disease in Holland will throw more light on this point. 



At the Department's seed-testing station in Dublin large numbers of 

 samples of flax-seed from various parts of the world are tested annually ; 

 and since the Colletotrichum disease is transmitted through the seed, we 

 decided to investigate representative samples of flax-seed from widely 

 different sources, to ascertain whether any of them carried the disease. 



For this purpose seed from various countries was sown in pots of steri- 

 lized soil, and the seedlings carefully watched for the appearance of the 

 disease. In this way seedlings affected with it have been grown from seed 

 coming from Eussia, Holland, Canada, and Japan. Hibernating mycelium 

 of Colletotrichum linicolum, which produced conidia on incubation, has also 

 been found in seeds from samples coming from the United States of 

 America. 



We have no reason to doubt the authenticity of the sources of origin of 

 the samples of seed tested ; but, of course, we are not personally able to 

 vouch for their accuracy, since they were not forwarded direct to us for the 

 purpose of the investigation. It is, however, to say the least, exceedingly 

 probable that the disease described by us occurs, not alone in Ireland, but 

 also in the other countries named. It would not be surprising if further 

 research should show that it exists more or less wherever flax is cultivated. 



X. — Summary. 



The present communication deals with a disease of flax seedlings which 

 was reported as a ease of " yellowing," but for which this designation is not 

 regarded as being particularly appropriate. 



The symptoms of the disease are described in detail, chief amongst 

 them being the development of spots on the leaves and lesions on the stems 

 leading, in many cases, to the death of the seedlings by a process resembling 

 " damping off." 



A species of Colletotrichum was found associated with the disease. This 

 fungus was isolated and grown in pure culture; and infection experiments 

 were carried out which proved it to be the cause of the malady. 



The disease to some extent resembles the so-called "Flax Canker" 

 attributed to Colletotrichum lini in the United States of America. It 

 resembles more closely a disease ascribed to an unnamed species of 

 Colletotrichum in Holland. 



The fungus, proved to be the cause of the disease, is described as a 

 new species under the name Colletotrichum linicolum. 



