DEPARTMENT OF EXPERIMENTAL EVOLUTION. 135 



correlation. Dr. Harris points out the value of knowing the correlation 

 in egg-laying, milk-yield, crop-production, and the Uke between first and 

 second year, as enabling one to predict the second year's performance 

 from that of the first. A series of illustrative cases is given in ''The 

 value of interannual correlations" {Amer. Nat., 49, 707-712). 



The distribution and correlation of the sexes (staminate and pistillate 

 flowers) in the inflorescence of certain weeds has been worked out by 

 Dr. Harris (Bull. Torrey Botanical Club, 42, 663-673) from data of 

 Cannarella. 



Dr. Harris has also pubhshed "An outline of current progress in the 

 theory of correlation and contingency," in the American Naturalist 

 for January. Also a note on "standard dairy score-cards" (Science, 

 Oct. 8, 1915). 



"The incidence of the beetle Bruchus on beans" has been studied 

 incidentally by Dr. Harris. His analysis shows that the larger pods 

 are more apt to be parasitized, probabty because of some relation of 

 greater fitness to the size of the beetle. 



GENERAL CONSIDERATIONS. 



In a subject of such complexity as biology it is often desirable to 

 spend somie time in synthetic or general analytic discussion. The 

 Director has written a paper on the topic "The form of evolutionary 

 theory that modern genetical research seems to favor" (American Nat- 

 uralist, Aug. 1916), in which the preformation view of phylogenesis — the 

 view of orthogenesis — is accepted as a very useful hypothesis, and one 

 with the most numerous probabilities in its favor. Some of the evi- 

 dence for it is set forth and certain consequences of it as a theory. 



A second general paper is an effort hj Dr. E. C, MacDowell to clear 

 up the differences that have developed between Castle and other 

 geneticists, or rather to harmonize Castle's views with current theory. 

 This paper, "Piebald rats and multiple factors," appeared in the Ameri- 

 can Naturalist, December 1916. 



The "\^Tiitman manuscripts have been brought forward bj^ Dr. 

 Riddle, and, it is expected, will be completed by the end of the year. 



