SENECIO JACOBAEA & CALLIMORPHA JACOBAEA POOLE. 283 



croppers, and are in consequence a check on the spread of the 

 weed in enclosed lands. Horses too, are not known to be 

 affected by it for they not only avoid it in the field but also 

 where they find it in the hay. Cattle, on the other hand 

 while more discriminating in their feeding than sheep, are 

 careful to avoid eating it in the open but they have not the 

 same opportunity for rejecting it when it is dried and mixed 

 with hay in the byre. It is then they suffer, and it is now 

 stated on page 161 of "The Farm Weeds of Canada" that 

 Dr. Pethick of Antigonish has proved that Ragwort is the 

 cause of the Pictou County Cattle Disease. This being so it is 

 all the more apparent that trial should be made of any means 

 that may reasonably be expected to further check the spread 

 of so noxious a weed in Canada. 



When commenting to me on the relation of Ragwort with 

 the Pictou County cattle disease Sir. E. D. Prain related an 

 Indian experience that was apposite to the matter. Speaking 

 of the use of sorghum as forage when the plant was fully 

 grown and cut down, he remarked that care was necessary to 

 keep cattle from the fields while the plant was still young as it 

 then contained hydrocyani c acid in poisonous quantity. Not 

 so when the sorghum was well grown, but it sometimes 

 happened that the season was wet after the harvest and then 

 instead of drying, the plant sent up fresh shoots which were as 

 poisonous to cattle as the young plant. 



It would have been superfluous and presumptuous on my 

 part to dwell on the relation between the Cinnabar moth and 

 Senecio when so great an authority as the Natural History 

 Department of the British Museum accepts it without reser- 

 vation. 



Mr. C. W. Brachen, B. A., F. E. S., of Plymouth writes 

 me as follows: 



"I have met the larvae of the Cinnabar moth, when 

 sweeping, for years, but only on Ragwort and Groundsel 

 (S. vulgaris). I have never seen it on Coltsfoot. It can be 



