13 



the new tubers to kill as of the old. It seems probable that the very 

 young tubers are only slightly poisonous, becoming more so later in 

 the season, until, when fully matured, they are as poisonous as the old 

 ones. 



Feeding Tubers of Water Hemlock from Nebraska. 



The material fed to sheep in Table No. IV was collected in Nebraska 

 and fed in Nevada. 



TABLE No. IV 



POISON PABSNIP (WATER HEMLOCK). WILTED TUBERS FROM NEBRASKA 



FED TO SHEEP 



The Nebraska material was partly dry, and had lost about half its 

 weight, so that in Table IV the amount fed is doubled. 



From the results it would appear that the Nebraska rootstocks were 

 less poisonous than those from Nevada. As seen by Table No. I, two 

 ounces of the Nevada material, when fed fresh, usually caused serious 

 poisoning or death, while it took four ounces of the Nebraska material 

 to cause symptoms. These feedings seem to show that the water hem- 

 lock is less dangerous in some parts of the country than in others. 



Feeding Young Leaves to Sheep. 



More losses of stock from water hemlock poisoning occur in the early 

 spring than at any other season, and it is by no means clear that such 

 losses are always due to the eating of pulled tubers. For this reason 

 it seemed probable that the green shoots of the plant are poisonous 

 when they first appear in the spring. Table No. V summarizes the 

 results of feeding young leaves to sheep : 



TABLE No. V 

 POISON PARSNIP (WATER HEMLOCK). YOUNG TOPS FED TO SHEEP 



Fed green parts of leaves only: 



101 i 5-6-20 I 9:25 a. m. 



10:00 a. m. 



Slight trembling 



only symptom Recovery 



Ten feedings were made. In the series of feedings made early in 



