BOOK REVIEW 71 climate. In tropical America the livestock and plants survived to a certain extent, still they are mixed societies of Europeans, Amerindians and slaves. Only exception was Queensland in Australia, though tropical, became a Neo Europe, because there indigenous population was less. Weeds played an important role in success of European agriculture. They replaced indigenous flora, which were un'able to withstand the livestock these Europeans brought with them. Peaches and English grass in North America, Giant thistle and Wild antichoke in pampas thrived in the changed ecosystem. Even in Australia by 1937 most of the weeds were of European origin. Weeds grown in a disturbed environment, stabilized the soil, prevented sunrays and helped other plants to grow. When the disturbance was over they gave way to other plants. Thus they played an important role when Europeans intruded into Neo Europes. Like wise animals performed crucial role in sustaining the invaders. The domestic animals of indigenes were inferior to horse, cattle, pigs, goats etc., of Europeans. Pigs provided for nourishment. Cattle converted unedible plants into meat. These animals prospered in Americas and Australia. Like wise horse was instrumental in many of the conquests. Honeybee was an important creature imported in to Australia which is now one of the largest exporters of honey. Rates were an unwanted addition. The exchange of plants and animals between the New world and Old world was unequal, and most of the weeds and animals of New world failed to prosper in Old world. The pathogens were the most important of the three factors which to a large extent determined the future masters of Neo Europes. As in the case of Atlantic Islands (Canaries) diseases proved fatal to the indigenes. Small pox, Measles, Diptheria, Trachoma, Whooping cough, Chicken pox, Bubonic plague, Malaria, Typhoid, Cholera, Yellow fever, Dengue fever and Dysentry were unknown in Neo Europes. The epidemics of small pox in North America in 1630 left 50 per cent dead. Respiratory infection, dysentry, veneral diseases predominated Australia. Even the disappearance of highly cultured people in Eastern United States by 1700 AD was due to some kind of epidemic disease. The exchange of infections was also unequal. The colonization of New Zealand is a most vividly illustrated part in the book. New Zealand was ideal for agriculture and pastoralism. It was mostly covered with forests when humans, that is Polynesians (Maoris) arrived here. It had a unique fauna. When Polynesians arrived, only land mammal present was bat. Tuatara, flightless birds were other unique creatures. Maoris had only one domesticated animal, dog, and introduced sweet potato called 'Kumara'. When Europeans came, they were already burning forests and raising crops. Still Maoris were dependant on wild sources of food, plant and animal. When Europeans came, there were only four mammals, the