De Vries gave his mutation theory on organic evolution while working on

1. Pisum sativum

2. Drosophila melanogaster

3. Oenothera lamarckiana

4. Althea rosea

The ultimate source of allelic variations is:

1. Genetic recombinations 

2. Mutation 

3. Genetic drift 

4. Natural selection 

De Vries based his "Mutation Theory" on his observation on:

(1) Pisum sativum

(2) Drosophila melanogaster

(3) Oenothera lamarckiana

(4) Caenorhabditis elegans

Theory of 'Saltations' was given by 

(1) G Mendel

(2) Hugo de Vries

(3) J B S Haldane

(4) H J Miller