438 Biology in America 



But not alone in commerce has biology played its part. 

 It has entered the courts of justice and aided in disentangling 

 the knotty problems of the law. 



In murder trials the guilt or innocence of the accused 

 may hinge upon the kind of blood in a stain upon his clothes, 

 whether human or not. Until recently there was no certain 

 test. But through the discovery .of the blood test, made 

 chiefly by the English physiologist Nuttall, we now know 

 how to determine this. For if human blood be injected into 

 a rabbit, there develops in the blood of the latter an "anti- 

 body" which produces a white precipitate with human blood. 

 All that is necessary then, in diagnosing a blood stain, is to 

 soak the piece ^f clothing in salt solution and mix a little of 

 the latter with the "anti-human serum" from the rabbit, 

 a resultant white precipitate indicating the presence of human 

 blood. An interesting corollary of this discovery is the fact 

 that "anti-human serum" will produce a precipitate, though 

 not so marked, with an ape's blood, and that the amount of 

 precipitate formed decreases progressively the less close the 

 relationship between man and the animal tested. 



Not many years since the U. S. Department of Justice 

 found itself in a muddle over the status of certain lands in 

 the Mississippi "bottoms" in eastern Arkansas. These lands 

 were covered by timber of great value and were furthermore 

 very valuable for agriculture after the timber was removed. 

 Now it so happened that certain lumber "barons" having 

 exhausted the supply on neighboring lands began casting 

 covetous eyes upon the rich "bottoms." In 1847 when the 

 original survey of this district was made the land in question 

 was entered on the maps as "permanent lake." So the 

 barons decided to gain possession, not by purchase of the 

 lands, but by purchase of "riparian rights" along the old 

 ' ' lake ' ' shore, which according to the law would entitle them 

 to possession of the "lake" bottom, when the latter receded 

 or dried up. But Uncle Sam threw a clog into their nicely 

 oiled machine by bringing suit against them on the grounds 

 that the survey was wrong and that lakes had existed there 

 in the imagination of the surveyors rather than upon the lands 

 themselves. Then the Department of Justice turned to the 

 biologist for assistance and asked Professor Cowles of the 

 University of Chicago to appear as an expert witness. 



There were many lines of evidence which Professor Cowles 

 found, all closely related and corroborative one of the other. 

 These were in part botanical and in part physiographic. He 

 found for example that at the time when these supposed lakes 

 existed there was an upland forest standing there of great 

 age. The lumber interests tried to show that many trees 



