XXViil CONTENTS 
PAGES 
CHAPTER XXII 
Tue MonocotyLeDONs 
MONOCOTYLEDONS.—Their characteristics. . . . . ... . . . 481-483 
DRUG YIELDING MONOCOTYLEDONS.—The orders and families 
of monocotyledons yielding drugs with characteristics of the 
families. Tables of official and unofficial drugs with names of 
drugs, parts used, botanical origins and habitats. . . . . 
CHAPTER XXIII 
Tue DicorTyLepons 
DICOTYLEDONS.— Their characteristics... Ss a 
DRUG YIELDING DICOTYLEDONS.—The sub-classes, orders and © 
families of Dicptyledons yielding drugs. Tables of official — 
and unofficial drugs under each family description, with the — 
drug names, parts used, botanical origins, and habitats. . . . 499-61! 
CHAPTER XXIV 
EcoLocy 
INTRODUCTION.—Ecology defined. Environmental factors. 
PLANT COMMUNITIES AND ASSOCIATIONS.—Definitions. 
Classification based on relation plant associations have assumed 
in regard to water. Characteristics of Hydrophytes, Helophytes, 
paca de Xerophytes, Mesophytes and a ese 
RELATION OF PLANTS AND ANIMALS.—aaksinypon ae PLANTS: 
The Sundews, Venus Fly-trap, Submerged Dionza, the Pitcher 
Plants, the Bladderworts, the Butterworts and their biological 
relations. Significance of the carnivorous habit. . . . . .— 
CHAPTER XXV 
GENETICS AND EvoLuTION 
SCOPE OF GENETICS.—Genetics and Bai ; 
Biereditary eubstance 3 a Ne ee 
and his experiments. 
Laws. Structure of the Chiveuceaint: 
mosomes. Distribution of chromosomes tura 
and fertilization. Distribution of genes. -Dominants a 
recessives. Genotype and Phenotype. Monohybrids. Re SU 
of crossing individuals with one pair of contrasting | 
