A five year old helps to mind some Lion cubs in Tennesse Zoo. (Photo by Hulton Archive/Getty Images). 1st August 1923

A baby hippopotamus in captivity pulls a gentleman along in a trap. (Photo by Topical Press Agency/Getty Images). December 1923

A baby and cat in a suitcase. (Photo by MacGregor/Topical Press Agency/Getty Images). June 1924

Two kittens, a dog and a soda siphon. (Photo by Fox Photos/Getty Images). May 1929

Motorcyclist Triss Sharp and his pet lion cub mascot at Crystal Palace in London. (Photo by Fox Photos/Getty Images). 3rd April 1930

A zookeeper handles a baby crocodile. (Photo by Fox Photos/Getty Images). 28th November 1930

Noel Burnet gives a piggyback to a koala bear and her baby at Koala Park, Sydney. (Photo by Fox Photos/Getty Images). 15th May 1931

A young exhibitor arrives with her kitten on a lead at the National Cat Club show at Crystal Palace, London. (Photo by Fox Photos/Getty Images). 2nd December 1931

Billy, a baby hippo, takes a swig from a bottle held by his keeper before his first public appearance. (Photo by Fox Photos/Getty Images). 30th July 1932

A keeper at Whipsnade Zoo holding three tiger cubs. (Photo by Fox Photos/Getty Images). 24th August 1934

The young daughter of a hunt member wears a riding hat and an apprehensive look as she sits with two hound puppies. (Photo by Fox Photos/Getty Images). 10th September 1934

Mother and her three kittens could not resist the pail of milk, recently collected from the cow, and are seen helping themselves. (Photo by Fox Photos/Getty Images). September 1934

4 week old piglets on a farm at Sparsholt, Berks. (Photo by Fox Photos/Getty Images). February 1936

A young farmer adapts a yoke to bring in a fine pair of new born lambs from a distant field in Cleeve, Gloucestershire. (Photo by Fox Photos/Getty Images). 11th February 1936

A young Welsh boy has adopted one of the new arrivals on a farm at Rhondda during the lambing season. (Photo by Richards/Fox Photos/Getty Images). 7th March 1936

A close-up of a baby chimpanzee at Edinburgh Zoo. (Photo by Fox Photos/Getty Images). 25th July 1936

Three month old lion cubs bare their teeth at the Chessington Zoo in Surrey. (Photo by Hulton Archive/Getty Images). July 1936

A line of Great Dane puppies drink milk from bowls while their mother looks on. (Photo by Fox Photos/Getty Images). 1st August 1936

Wednesday the chimpanzee enjoys her first cigarette since the birth of her baby, Andrew, at Edinburgh Zoo. The two chimps are now allowed into the outdoor enclosure adjacent to their cage. (Photo by Martin/Fox Photos/Getty Images). 3rd September 1936