CARROT FAMILY. 77 



3 p.m. nine were found dead and several sick, one of the 

 latter dying while the herd was being removed. On ex- 

 amination of the place where the dead animals were 

 found, a piece of marshy land near the shore of Lake 

 Winnipeg, it was discovered that the whole area was 

 overgrown by the young shoots of the Water Hemlock. 

 The stomach contents of the dead animals proved to be 

 composed chiefly of this young growth with a few roots. 

 In this particular area cattle had pastured in former 

 years with impunity, the young Water Hemlock having 

 been concealed by the previous year's growth of marsh 

 grass, but this season the grass cover had been burned 

 off. Another peculiar feature of the case was that the 

 younger members of the herd were not affected. This 

 apparent immunity was found to be due to their having 

 been driven away from the tempting shoots by the older 

 animals. 



Some writers state that the plant is most poisonous 

 in winter and spring. Others believe that the effects in 

 autumn are just as deadly. All agree, however, that 

 during the hot summer season a larger quantity may be 

 eaten without harmful results. Jacobson has discovered 

 the reason for this. In his investigations of the proper- 

 ties of cicutoxin, the poisonous constituent, he found that 

 it is very sensitive to rises in temperature, becoming 

 polymerized by heat. 



The poison is very rapid in its action, and a very small 



quantity will produce death. Soon after eating severe 



aJbdominal pain manifests itself. Great mental 



Symptoms . 



excitement develops into a frenzy. There is 

 often frothing at the mouth. Respiration is laboured and 

 often irregular. The pulse is intermittent. Convulsions 

 follow and death ensues, sometimes within fifteen min- 



