16 



the plates for Mr. E. R. Boyer's article " On the Mesoderm in 

 Teleosts, especially the Source of the Mesodermic Elements 

 which form the Limb-Bud," is in progress ; and papers by Mr. 

 W. Whitney, " Notes on the Nervous System of Thyone bri- 

 areus, Lesueur," and by Mr. H. P. Johnson, "Studies on Direct 

 Nuclear Division," are also finished. 



These papers will all be published in the Museum Bulletin as 

 rapidly as the plates illustrating them can be engraved. 



Since the last Annual Report Nos. XV., XVI., and XVII. of 

 the " Contributions from the Zoological Laboratory " have been 

 issued in the Museum Bulletin, viz.: — XV. Studies on Lepi- 

 dosteus, by E. L. Mark, (9 plates,) February, 1890. — XVI. On 

 the Egg Membranes and Micropyle of some Osseous Fishes, 

 by C. H. Eigenmann, (3 plates,) March, 1890. — XVII. The 

 Histology and Development of the Eye in the Lobster, by G. H. 

 Parker, (4 plates,) May, 1890. 



The meetings of the Zoological Club have been continued with 

 regularity, and with the usual interest. 



The instruction in Comparative Osteology, in charge of Dr. D. 

 D. Slade, Nat. Hist. 21, during the academic year 1889-90, has 

 been given by means of lectures, laboratory work, and frequent 

 examinations. The course has been followed by two Seniors, 

 two Graduates, and by three Special Students. 



The course Nat. Hist. 5 was conducted in 1889-90 on the 

 same plan as in the previous year, by Mr. G. H. Parker and 

 Professor W. G. Farlow, assisted by Mr. W. A. Setchell. The 

 number of students taking the course was larger than in any 

 previous year, and inasmuch as the room was necessarily also 

 occupied during a part of the time by the members of another 

 course, whose students were more numerous than usual, it re- 

 quired careful arrangement to provide each student with the 

 amount of space necessary for good work. The completion of 

 the new Botanical Rooms, in which, in the future, the instruc- 

 tion of the botanical portion of Nat. Hist. 5 will be given, will 

 relieve the crowding unavoidable during the present year. 



The number of students taking Nat. Hist. 23 was also larger 

 than usual, and, it being impossible to find places for them all in 

 the Reptile Room, where the course had been given for the past 

 few years, by the kindness of the Director of the Museum the 

 class was allowed to use temporarily one of the new Geological 



