54 



The Plant World. 



The Primrose Garden of Professor de Vries occupies about 

 one-third of the entire botanical garden of the University of 

 Amsterdam, and now contains only primroses with which he is 

 continually experimenting. The primroses were first discov- 

 ered by Professor de Vries in a state of mutability at Hilversum, 

 Holland, in 1889. Some of these mutable forms were transferred 

 by him to his garden in Amsterdam. Professor de Vries has re- 

 peatedly visited the original primrose field at Hilversum, in 

 order to observe the forms still growing there. The remaining 

 primroses in the original primrose field are disappearing owing 



Fig. 1. Part of Primrose garden, in the Botanical Garden of the University of 

 Amsterdam, where the experiments of Professor Hugo de Vries on mutation are conducted . 



to the fact that pine trees have been planted there, which are 

 rapidly! crowding out the plants. Quite a number of forms in 

 various stages are^still to be observed on the field at Hilversum, 

 as I noticed when I visited this field on one occasion, in company 

 with Professor de Vries. The primroses brought from Hilver- 

 sum to Amsterdam have been increased greatly in number and 

 new forms have been produced from the original individuals. 



The primrose garden at Amsterdam is arranged in two parts. 

 In one part the plants are grown inclosed in a house with a glass 



