Annual Meeting.] 
272 
[May 6, 
that good results can be easily obtained. It has also been ascer- 
tained, that no popular lectures can be so effective as such a well 
ordered series of talks made with the objects before the hearers . ” 
We have received an important addition to our Museum in the 
conchological collection of the late Edward R. Mayo. This 
was donated to the Society by the heirs of Mr. Mayo’s estate, 
and is adequately noticed farther on under the title of the proper 
division. 
Important changes have also taken place in the policy of the 
Teachers’ School of Science which are noticed under the proper 
heading. 
Permission to visit and study in the Museum on days when 
the public is not admitted has been granted to eight teachers 
representing eight schools and two hundred and nine pupils. 
Pupils from the Mass. Institute of Technology frequently apply 
for the privilege of studying in our collection of Mineralogy and 
Geology on closed days and are admitted. Professor Crosby 
uses our collections for the benefit of his classes at the Institute, 
and Dr. E. G. Gardiner has used the collections of anatomical 
preparations with his class and has had the privilege of opening 
the cases. Although this has been the practice for many years 
with reference to the Institute of Technology it has not been 
customary to notice the facts in the annual reports except in con- 
nection with the library which is also used by students of the 
Institute. 
Dynamical Zoology. 
Dr. R. T. Jackson has picked out series of molluscs to illustrate 
the following dynamical principles. The mechanical origin of 
the ostrean form of shell. Geomalic growth. The relations of 
the upper and lower sides of organisms to the influence of light. 
The progressive reduction in animal growth with increasing age 
in the individual. Some of these series are not completed, but 
they will be as soon as possible, and they, with others in prepara- 
tion, will be placed on exhibition in the dynamical collection in 
the Vestibule. 
A remarkably perfect and in some respects unique model of a 
fresh water perch has been completed by Mr. Denton, and will 
be placed in this collection. This, with other models and drawings 
