224 REPORTS OF INVESTIGATIONS AND PROJECTS. 



Although the quantitative results must await announcement until a thor- 

 ough study has been made of all the individuals collected, certain qualitative 

 results of importance may be stated at the present juncture. The occurrence 

 of mutation in several species from the leeward islands has been demon- 

 strated, thus confirming in principle the conclusion offered last year, based 

 upon the study of the snails of Tahiti and Moorea. The mutants may arise 

 in the older portions of the habitat of a species as well as in newly-acquired 

 territory. Finally, environmental factors do not seem to be the active or 

 direct causes of mutation or of variation as distinguished from mutation. 



Gudger, E. W., North Carolina State Normal and Industrial College, Greens- 

 boro, North Carolina. Grant No. 529. Investigation of the breeding 

 habits and the life-history of the gaff topsail cattish. $300. 



Thus far Dr. Gudger's work has consisted in collecting material, making 

 notes, and supervising the work of the artist making the drawings. The in- 

 vestigation is as yet in an early stage, and the results will not be ready for 

 publication for a year or two. 



Howard, L. O., United States Department of Agriculture, Washington, Dis- 

 trict of Columbia. Grant No. 250. Preparation of a monograph on 

 American mosquitoes. (For previous reports see Year Books Nos. 

 2, 3, 4, 5, and 6.) $3,000. 



The report for the past year is simply one of general progress. Messrs. 

 H. G. Dyar and Frederick Knab, both employees of the Bureau of Ento- 

 mology of the U. S. Department of Agriculture, have beeen working steadily 

 on the manuscript of the classificatory portion of the volume. Dr. Howard 

 has been working upon the features which deal with remedial work, and with 

 disease. He has taken several trips to investigate large-scale remedial work 

 being carried on. Mr. Knab has also been engaged in completing a series of 

 drawings of the early stages. The monograph is fast approaching comple- 

 tion, and will soon be submitted for publication. In the course of the work 

 two short papers by Mr. Knab have been published. (See bibliography, 

 pp. 45-52.) 



Mark, E. L., Harvard University, Cambridge, Massachusetts. Grant No. 



506. Study of maturation and early stages in the development of the 



ova of mice. (For previous reports see Year Books Nos. 5 and 6.) $300. 



The work under this grant has been carried forward successfully by Dr. 



Mark, in collaboration with Dr. J. A. Long, and the results are embodied in a 



paper about ready for publication. A preliminary account of some of the 



results reached in the study of the chromosome-number were presented at the 



New Haven meeting of the American Society of Zoologists in December, 



1907, and subsequently published in Science, as shown in the bibliography on 



pp. 45-52 of this volume. 



Time did not permit Dr. Long to carry very far that branch of the work 

 which had to do with the production of hybrids by means of artificial in- 



