490 Plant Physiology 



variation, construct curves and prepare a report which shall 

 include the results of the study made, together with an abstract 

 of one or more of such papers as the following : 



DAVENPORT, C. B. Statistical Methods. Pp. 19-41. 

 DAVENPORT, E. Principles of Breeding. Pp. 681-703. 

 HARRIS, J. A. Amer. Nat. 43 : pp. 350-355 ; ibid., 44 : pp. 19-30. 

 LUDWIG, F. Biometrika. 1: pp. 11-29. 

 PEARSON, K. Grammar of Science. Pp. 381^402. 

 SHULL, G. H. Amer. Nat. 36 : pp. 111-152. 



Compare, if possible, the curves of variation with respect to any 

 character in two populations grown under dissimilar conditions. 



FIG. 140. Dahlia flowers with bursting anthers. [Photograph from 

 Bureau Plant Industry.] 



Heredity. Laboratory work upon heredity covering only 

 one or two periods may be only suggestive, or may give opportu- 

 nity for the presentation of materials which may be subsequently 

 worked up as a report. Practical studies are preferably confined 

 to the following : 



