This piece of work was undertaken as the result of certain observations made during class-work on irregular nutrition. This particular species of Cuscuta was being successfully grown at the time in Glasgow Botanic Gardens, and my sincerest thanks are due to Mr Banks, the Curator of the Gardens, who has very kindly allowed me to have abundant material at all times, and has also provided me with various host-plants upon which to grow the parasite. He has also allowed me to make observations on the plants growing in the Gardens, and to take photographs whenever I wished.