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.
7 Common Reasons for Coughs. A cold or allergies can cause mucus to drip down your throat. This postnasal drip can touch on nerve endings, leading to either a wet or dry cough. A cough due to postnasal drip will usually be worse at night, and you may also have a tickle or scratchy feeling at the back of your throat.