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.
During sleep, your facial muscles and mouth move abnormally. This causes breaks in your regular sleep pattern, and you may be waking up in the middle of the night because of dry mouth. If you feel like you need to wake up frequently to take a drink of water, it could be sleep apnea.