Annual Meeting.] 314 [May 5, 



Inst. Technology, one in Zoology from the Boston University, 

 these three being under the charge of the Curator ; also, one in 

 Botany and one in Physiology, from the Boston University, both 

 of these last being under the charge of Mr. B. H. Van Vleck. 

 There has been unusual activity in this department, and its teach- 

 ing power has been augmented by the addition of selected speci- 

 mens and diagrams. The principal among these is a series of 

 twenty-five models, given by Mr. R. C. Greenleaf. They are ac- 

 curate copies of Hatscheck's illustrations of the embryonic stages 

 of Amphioxus, showing the development of the endoderm, ner- 

 vous chord, notochord, mesodermal somites and endoderm. This 

 is done with such clearness that even a beginner in zoology can 

 with their aid be made to comprehend the evolution of the prin- 

 cipal layers in the body of a vertebrate from the single cell of 

 the ovum and the two primitive layers of the gastrula. Models 

 are evidently great aids in the teaching of general principles and 

 our Laboratory needs more of them. 



The lecture room in the basement has become too small for the 

 accommodation of students, and the Society has begun the refit- 

 ting of the quarters formerly occupied by the janitor with the inten- 

 tion of making a more spacious and better ventilated class room. 



Summer Laboratory. 



This department, as in former years, has been carried on by 

 means of a donation from the Woman's Education Association, 

 whose members continue to show a very gratifying interest in our 

 work. 



The Curator being absent, the entire charge of the laboratory 

 devolved upon the voluntary labors of Mr. Van Vleck who con- 

 ducted it with his usual ability and success. 



The number of students were thirteen in all, four women and 

 nine men. The average time of each student in attendance was 

 four weeks and one day. The average of time for each student 

 was larger than in previous years, showing a gratifying improve- 

 ment in this respect, though the whole number of students was two 

 less than last year. As we have repeatedly said, the influence of 

 this laboratory is not to be measured by the number of students. 

 For example, we have good reason for thinking that Mr. Van 

 Vleck's work during this last summer has materially influenced the 

 future of science-teaching in two colleges, and in the public schools 



