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.
Symptoms are often worse when waking up from sleep and when talking. The wet cough may be the last symptom left after a common cold infection. Depending on the cause of your productive cough, other symptoms may include: 1  breathlessness; 2  fever; 3  cold and flu symptoms; 4  wheeze; and. 5  chest pain.ther, less common causes of a wet cough include: 1  bronchiectasis (a condition where the airways are damaged and abnormally wide causing a persistent, wet cough); and. 2  cystic fibrosis (an inherited condition that causes excessively thick mucus secretions in the airways).