LUPINES AS POISONOUS PLANTS. 29 
1914 the experiments were by forced feeding, so that the animal 
received the total quantity in a short period of time; while in 1910 
and 1911 some of the animals received large quantities, but the feed- 
ing was distributed over a long period. Although in some cases as 
much as 8 pounds was fed in a single day, this was eaten in a more 
or less leisurely way. 
In 1912 two sheep, Nos. 175 and 168, were drenched with the fruit, 
No. 175 receiving 1.435 pounds and No. 168 4.198 pounds, and 
showed no symptoms, although the 1914 experiments indicated that 
the toxic dose of fruit is about 14 pounds. Sheep No. 175, however, 
received its lupine in three doses, between 10.30 a. m. and 3.30 p. m.; 
it is possible that this animal might have been poisoned had it re- 
ceived the material in a single dose, as the quantity given was close 
to the toxic limit. But sheep No. 168 received 4.198 pounds, be- 
tween two and three times the toxic dose as determined in 1914; 
this material was given in six doses, between 8 a.m. and 7 p.m. It 
seems probable that the only reason this animal was not poisoned 
was because of the length of time during which the material was 
given. 
It appears to be a fair inference that the excretory apparatus of 
the sheep can take care of the toxic substance of the lupine provided 
the quantity given at any one time does not reach the toxic limit. 
It is hoped to carry on later detailed experiments to show just how 
this is done—experiments for which adequate facilities have not been 
available thus far. It is probable, however, that this excretory work 
is done largely by the kidneys, since preliminary experiments with 
other toxic substances upon sheep indicate that the kidneys are 
very efficient in the removal of some toxic substances. It has also 
been shown by others that the lupine alkaloids are found in the 
urine. The failure to get results in the earlier experiments was due 
to the fact that the sheep did not get at any time more than the 
excretory apparatus could remove before the toxic limit was reached. 
LUPINE NOT A CUMULATIVE POISON. 
The lupines as poisonous plants do not have a cumulative effect. 
This has an important bearing on range management of sheep, for 
it is evident that sheep may graze continuously on lupines with no 
bad results, provided the toxic limit is not reached at any one time, 
Inasmuch as the toxic dose is a fairly large quantity, and sheep do 
not ordinarily show any special fondness for the lupmes, well-fed 
animals are not likely to be poisoned by lupines. It is only when, 
for some reason, they eat an unusually large quantity that losses 
occur. This is discussed in more detail under ‘‘ Range conditions 
under which sheep are poisoned” on page 39. 
