] "I ^ settlers— old and new 



their time running about on three legs — which many of 

 them do not seem to mind too much until one of the re- 

 maining three is put out of commission. When that hap- 

 pens they have to do something about it and what the 

 wiser of them do is to approach their masters with an up- 

 lifted paw from which the master then extracts a section of 

 a little three- or four-seeded fruit provided with sharp pro- 

 jecting spines perhaps an eighth of an inch long. The seeds 

 were only thumbing a ride into new territory and if fortune 

 favors the seeds rather than the dogs, they will come up 

 next summer as an inoffensive-looking prostrate weed with 

 small compound leaves and humbly pretty little yellow 

 flowers. Few inhabitants of the region have escaped some 

 acquaintance with the fruit because it sometimes gets in- 

 side a human shoe and is said in the old days to have some- 

 times punctured a bicycle tire— whence the local name, 

 "puncture vine," for the plant. 



Many probably do not connect the fruit with the fa- 

 miliar weed, but Linnaeus knew all about it two hundred 

 years ago and gave it its current botanical name — Tribulus 

 terrestris. The first half of this name is Latin for those 

 wicked iron balls with spikes so arranged that one is always 

 pointing upw^ards. Medieval ingenuity scattered them, over 

 the ground when enemy cavalry was expected to attack. 

 Linnaeus was only borrowing an ancient name for a thorny 

 plant and I am not sure whether it was first applied to the 

 seed or to the weapon. In any event, here is another case 

 where nature was the first inventor of a device man later 

 hit upon for himself. 



But how did it happen that Linnaeus knew about this 

 inconspicuous weed growing way out in Arizona at a time 

 when even the Spanish fathers were but precariously 



