230 REPORTS OF INVESTIGATIONS AND PROJECTS. 



Still Others presented before the meeting of the International Zoological Con- 

 gress in Boston. Dr. Wilson has in preparation two extended papers based 

 on these results, and others will follow as the material is worked out by 

 himself and his students. 



The results thus far obtained are in part entirely new, in part an extension 

 and confirmation of Dr. Wilson's earlier work. While too complex to admit 

 of brief review, a list of some of the results in which he is most interested is 

 appended : 



( 1 ) The new phenomenon of the "supernumerary chromosomes" has been 

 brought to light (a paper on this subject is well advanced for publication), 

 which gives new and important data bearing on the theory of the individu- 

 ality of chromosomes and the origin of the unpaired sex-chromosome. 



(2) A new type of chromosome-couplings has been discovered in the 

 Hemiptera, which gives a possible explanation of character correlations in 

 the adult. 



(3) Constant chromosomal differences have been found between forms so 

 nearly related that they can not be distinguished otherwise by systematists. 

 This offers a possible explanation of "physiological species." 



(4) A mass of new data has been obtained bearing on the problems 

 of synapsis, reduction, sex-production, and Mendelism. A long time, pos- 

 sibly several years, will be required for the full study and analysis of these 

 data. 



It is Professor Wilson's intention to go into the field again to procure 

 additional material for study along the above and other lines. 



