He estimated how many species of insects lived on each plant species in England, and then extrapolated that figure across the whole planet. âIf we say 400,000, we shall, perhaps, not be very wide of the truth,â he wrote. Today, scientists know the Westwood figure is far too low.
Symptoms: A chronic dry cough that's worse at night, disturbing sleep, and sometimes with wheezing and shortness of breath. Causes: An irritating night cough is often the first sign of asthma, especially in children, but you can develop it at any age. It's also a sign asthma is worsening or not being well controlled.
In cases of persistent dry cough, see your health care provider. Dry cough can be present in people with various respiratory conditions, such as asthma, bronchitis, COPD, cystic fibrosis and many others. In most people, the problem gets worse at night due to additional CO2 losses.