ARCHITECTURE OF THE GERMPLASM 249 



8. LINKAGE IN OTHER ORGANISMS 



The phenomenon of linkage has already been observed 

 in various other organisms besides Drosophila. Even 

 in Mendel's classic peas White demonstrated four link- 

 age groups of characters and seven pairs of chromo- 

 somes. It is doubtful if Mendel himself ever heard of 

 chromosomes for he died in 1886 and Boveri's pioneer 

 work on chromosomes had only then recently appeared. 

 A list of a few of the organisms in which linkage has 

 been reported is given below. 



Organisms that show linkage Author 



Sweet pea Bateson and Punnett 



Snapdragon, Wheat Baur 



Primula Altenberg. Gregory 



Maize Emerson. Breggar. 



Lindstrom. Jones 



Tomato Jones 



Beans. Oats Surface 



Evening primrose Shull 



Drosophila virilis 1 



busckii I Metz 



repletaj 



Silkworms Tanaka 



Grouse locust Nabours 



Pigeon Cole and Kelly 



Rat. Mouse .Castle and Dunn 



Rat Ibsen 



Rabbit ...Castle 



