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THE AMERICAN NATURALIST 



[Vol. LIV 



problem and the facilities at their disposal or, in other words, 

 upon the amount of funds available for this project. 



In order to advance the genetic analysis of Crepis virens and 

 C. tectorum now under way to a stage favorable to carrying out 

 the interspecific hybridization studies properly, calls for green- 

 house equipment, technical assistance, supplies and labor which 

 are not at present available. Some provision for the collection 

 of seed in foreign countries should also be made. There is no 

 prospect at this time that these facilities will become available 

 in the near future. It is recognized that the expansion of this 

 project will require a larger proportion of the time of the two 

 investigators now engaged on it and the workers concerned stand 

 ready to meet this requirement. 



My purpose in going thus into detail is two-fold. First, so far 

 as I am aware, no other geneticists are working extensively with 

 this genus, and it should be clearly understood that under exist- 

 ing circumstances there is little prospect of rapid progress with 

 my own investigations. Yet the work has gone far enough to 

 accumulate material of very great promise. It is hoped, there- 

 fore, that means will be found to support adequately the investi- 

 gations of Crepis virens and C. tectorum now under way. Sec- 

 ond, it is highly desirable that other geneticists also contribute 

 to the analysis of the two species named above and especially 

 that they proceed with similar investigations, accompanied of 

 course with cytological studies, on other species of Crepis. 



Ernest B. Babcock 



LITERATURE CITED 

 1. Britton, N. L., and A. Brown. 



1918. Flora of North America. N. Y. 



1914. A Critical Study of the Cytology of Crepis virens. Arch. f. 

 Zellf., Bd. 12. 



3. Juel, H. O. 



1905. Die Tetradteilungen bei Taraxacum and anderen Cichorieen. K. 

 Svensk. Vetensk. Akad. Handl., Bd. 39. 



4. Morgan, T. H. 



1919. The Physical Basis of Heredity. N. Y. 



5. Robinson, B. L., and M. L. Fernald. 



1908. Gray's New Handbook of Botany. 



1909. Zur Kenntniss von den Tetradteilungen rler Compositen. Svensk. 



Botanisk. Tidskrift., Bd. 3, p. 64. 

 1898. Chromosomenzahlen and chromosomendimensionen in der Gattung 

 Crepis. Arkiv. for Botanik., Bd. 15, No. 11. 



