treated, but from fatigue on the part of the teachers, and this state of affairs caused him to say in his annual report that "proper and wise forethought should long ago have given teachers a portion of every week besides the usual Saturday holiday for the pursuit of information needed for teaching new subjects." He believed that the efficiency of the individual teacher would be greatly increased by this expedient, and that the pupils would gain more than they lost by the shortening of the school hours.
At the request of the Superintendent of Schools the curator gave the following year ten lessons, which were directed mainly to the subjects put down in the course of study under the title of Elementary Science Lessons. In his course in Elementary Mineralogy, Professor Crosby followed the plan indicated by Mrs. E. H. Richards in one of the science guides—First Lessons in Minerals. The curator, for his course on Structure and Habits of Worms, Insects, and Vertebrates, used many specimens which had been tanned by a process which was then in use. Over twenty-eight thousand zoölogical specimens were given away in two years. Professor Crosby, with a class of sixty, continued the course of the previous year, giving lessons in the mineralogical laboratory of the Massachusetts Institute of Technology, and the specimens there studied were retained by the teachers.
In the winter of 1888-89 Professor Crosby, using for his auditorium Huntington Hall, gave a course of ten lessons on the geology of Boston and vicinity. "The object of the lessons was to acquaint the teachers of Boston and vicinity with natural opportunities by which they are surrounded, and specially to show them how to use these opoprtunities for their own culture and the benefit of their pupils. The subject was treated in accordance with the following scheme: (1) A general study of the physical features of the Boston basin and of the geological changes now in progress in this region; (2) a systematic study of the various minerals and rocks found in the Boston basin, together with the more characteristic kinds of structure whicb they exhibit; (3) a summary of the geological history of the district so far as that is plainly recorded in the rocks. The course was freely illustrated by maps and diagrams, also to a large extent by specimens, more than ten thousand of which were distributed. Special pains were taken at every step of the work to indicate the localities where phenomena such as were described in the lessons might be most advantageously studied. This comprehensive course formed suitable preparation for a second series of lessons, the principal object of which was to apply the principles taught by the first series to a thorough and detailed study of the physical history of the Boston basin. Each important lo-
