Pethybridge and Lafferty — A Disease of Flax Seedlings. 367 



It is stated that " such seeds are often diseased on the interior, the young- 

 seed leaves already bearing cankers or sore spots before the seeds germinate." 

 In our Colletotrichum disease we have not found a single case of attack of 

 any part of the embryo within the seed, and in this very important respect 

 our disease differs from Bolley's " Canker." 



In reply to our enquiry for information as to the description of Colleto- 

 trichum lini Professor Bolley was good enough to state that as he did not 

 consider himself to be a systematist he had refrained from describing the 

 fungus, leaving that to be done by others. This apparently has never been 

 done, and we are, therefore, in the unfortunate position of not being able to 

 compare our fungus with that believed by Bolley to be the cause of " Canker." 

 In 1915 Schoevers 1 published an account of a flax disease in Holland 

 which he ascribed provisionally to the attacks of a species of Colletotrichum 

 which Mr. Bolley informs us represents, in his opinion, the same organism as 

 he had observed in America. 



Schoevers' account of the disease is based upon specimens forwarded to 

 him from Friesland ; and apparently he had not personally seen the disease • 

 as it occurs in the field. He calls attention to sunken patches on the young 

 stems below the surface of the ground, but yet above the neck of the root; 

 to the browning and death of some of the lower leaves of the seedlings, and 

 to the fact that he found a fungus on all the affected plants, belonging, 

 apparently, to the genus Colletotrichum. He thinks that this Colletotrichum 

 is perhaps related to, or identical with, a species of Gloeosporium found by 

 him on the seed-bolls of flax from Sexbierum. 



Schoevers gives a careful description of the Colletotrichum observed by him, 

 and his account of the disease is illustrated with four figures. The account 

 is, however, evidently a preliminary one, and this is perhaps the reason why 

 no species-name is given to the fungus. The fungus was not isolated in pure 

 culture, and no infection experiments were made. The disease appears to be 

 rather rare in Holland, and Schoevers' note upon it was published apparently 

 with a view to calling the attention of inspectors and others to it, in order 

 that on some future occasion a more thorough investigation of it might be 

 made. We think it quite possible that our Colletotrichum disease may be 

 the same as that described by Schoevers in his preliminary communication. 



With the exception of the incomplete and preliminary accounts of the 

 two authors just mentioned we have not been able to discover in phyto- 

 pathological literature anything bearing on flax diseases resembling the one 

 which we have been studying. 



1 Schoevers, T. A. C. Voorloopige Mededeeling over eene nog onbekende, wellicht 

 niet ongevaarlijke ziekte van het vlas. Tijdsch. over Plantenziekten, xxi., 1915, p. 100. 



SOIENT. PEOC. R.D.S., VOL. XV., NO. XXX. 3 N 



