MUSEUM OF COMPARATIVE ZOOLOGY. 9 



The number of lectures in Zoology 9, given as usual by Pro- 

 fessor Jackson, was somewhat increased over that of last year, 

 the optional hour being nearly always made use of. 



In Zoology 9 a the work was chiefly on young stages of living 

 and fossil mollusks. 



The lectures in Zoology 10 covered the same ground as in 

 1901-02, when they were last given ; especial attention, however, 

 was given by Dr. Castle to questions of sex and its relation to 

 heredity. In the second half-year the influences of chemical and 

 physical agents on protoplasm and its activities were considered. 

 A number of problems connected with heredity, variability, and 

 the influence of environment have been studied by different indi- 

 viduals in this course, and the results of some of these will be 

 published. 



Zoology 13 was conducted by Professor Parker, and covered 

 the same ground as in 1902-03. It is intended to broaden some- 

 what the course next year to include sustentative tissues, so that 

 it will be a course in comparative histology, as was originally 

 proposed. 



As usual, special topics for investigation were assigned by Pro- 

 fessor Parker to the students in Zoology 16. The topics were 

 chiefly on sensory organs and their functions. The results of 

 several of these will be published. The lectures were substan- 

 tially the same as the ones delivered in 1901-02. 



The supervision of students engaged in researches (Zoology 20) 

 was divided, as proposed in the last report, among the older in- 

 structors of the department. Of the twelve students engaged in 

 research, seven worked under the guidance of the Director, two 

 each under Professor Parker and Dr. Castle, and one under Pro- 

 fessor Jackson. Additional time for the research work was in a 

 few instances gained by allowing the student to meet the labora- 

 tory requirements in some of the formal courses (Courses 10 and 

 16) by devoting his laboratory time to the topic of his investiga- 

 tion. In all cases satisfactory progress was made with the work, 

 and the results of several of the studies are ready for publication ; 

 indeed, two preliminary papers have already been issued as num- 

 bers 142 and 144 of the Contributions from the laboratory, — the 

 former embodying some of the results of breeding experiments 

 carried on for some time by Dr. Castle, or under his guidance ; 

 the latter some important histological results arrived at under 

 the supervision of Professor Parker. 



