20 BULLETIN 1274, U. S. DEPARTMENT OF AGRICULTURE 
port or in refutation of this claim. In one case, pig- 10, July 6, 1920, 
six fruits of the Xanthium were eaten with no deleterious results. 
Presumably they were digested. 
The experimental feeding of fruit to chickens may have some bear- 
ing on this question. Six mature burs coated with a stiff mixture 
of white flour and water were given to chicken 37. The dough was 
used to cover the spines in order to protect the chicken's throat. 
During the first 18 hours after feeding, 4 of the burs had disap- 
peared from the crop. Of the two remaining burs one had gone in 
90 hours, while the other did not move on for 186 hours. 
The first morning following the feeding the chicken was slightly 
depressed, but by evening the depression was almost entirely gone. 
At the end of the first 96 hours the animal's weight had dropped 250 
grams. After this time it rose slightly, but still remained about 200 
grains below the weight at the beginning of the feeding. After the 
last bur had gone the weight increased. The autopsy showed no 
effect of the burs. 
Chicken 32 was given 12 mature burs which were likewise coated 
with dough. Eighteen hours after feeding there still remained a 
mat of burs in the crop, possibly 8 or 9 in number; the clump was 
too large for counting. Forty-two hours after feeding, the clump of 
burs 'was still present, but a few were separated from the main ball. 
Sixty-six hours after feeding, 6 burs could be counted. These were 
separated from one another. Ninety hours after feeding, 4 burs 
still remained. In 97 hours only 1 bur remained and that one had 
disappeared in 114 hours. At the end of 42 hours the animal was 
slightly stupid, and the points of his comb were dark. There was a 
drop in weight of about 70 grams for a week following the feeding. 
Xo serious consequences resulted from these two feedings, but in 
each case it seems likely that there was a slight disturbance of a 
general nature. As soon as the cause of the trouble was removed 
there seemed to be prompt improvement. 
While the feces of these animals were not collected, they were un- 
der constant observation and it is believed that the burs were di- 
gested. 
To sum up the present state of our knowledge in regard to in- 
juries to animals from the use of the whole fruit, the statements 
made by other authors, quoted on pages 2—5, seem to be based on 
actual experience, and must be taken at their face value. It must 
be presumed, then, that swine may be injured by the fruit. The 
experience of the authors, however, indicates that swine do not. 
readily eat the burs and that injuries from this source, if they oc- 
cur, are somewhat rare. So far as chickens are concerned it is im- 
probable that, when left to themselves, they would ever take as many 
burs as were given in the experiments, and as these animals were not 
injured it may be fairly concluded that burs, under ordinary cir- 
cumstances, do not harm chickens. 
TOXICITY OF DRIED PLANT 
There were four experimental feedings of dried plant. In these 
feedings, estimating the material as green plant, pig 21 was killed 
with 1.71 per cenl of its weight of cotyledons. Pig 23 received of the 
plant in the young cotyledon stage at one time 1.54 per cent of its 
