C N T E N T S. a 



Page. 



The supposed relationship of whil e snakeroot to milksickness, or ' ; trembles " 5 



Historical introduction * 5 



Recent investigations 15 



Effect of white snakeroot on rabbits 15 



Extracts from dry plant 15 



Extracts from fresh plants preserved in chloroform 16 



Extracts from ash 17 



Effect of white snakeroot on cats 17 



Effect of white snakeroot on dogs . . . .' : . 18 



Effect of white snakeroot on sheep . . . 19 



Effect of white snakeroot on man 19 



Summary 19 



Mountain laurel, a poisonous plant 21 



Historical introduction 21 



Effect of mountain laurel on sheep 26 



Effect of mountain laurel on rabbits 29 



General symptoms of poisoning 30 



Active principle 30 



Remedial agents • 34 



Medicinal action 34 



Results of loco- weed investigations in the field 37 



Field work . 37 



Laboratory work on loco-weed investigations 39 



Summary of laboratory work ; 39 



The sources of arsenic in certain samples of dried hops 41 



Introduction , : r 41 



Origin of samples of hops examined 42 



Examination of hop soils 43 



The absorption of arsenic by the growing plant 43 



Impure sulphur as a source of arsenic 44 



Conclusions 45 



Apple leaf -spot caused by Sphaeropsis malorum 47 



Introduction. . .'. 47 



Cause of leaf-spot 48 



Cultural studies 49 



Inoculation experiments 50 . 



Conclusions 52 



Source of infection 52 



Treatment 53 



Bibliography 54 



The immunity of the Japanese chestnut to the bark disease 55 



The extent of the bark disease ' 55 



An immune variety , • 55 



Index 57 



« The seven papers constituting this bulletin were issued in separate form on Jan- 

 uary 28, February 20, January 28, January 28, February 21, March 12, and February 

 10, 1908, respectively. 



121 3 



