The eggs of the tern alluded to furnished the opportunity for a lesson. A sufficient number of these eggs were opened and prepared to enable students to master the methods and learn what to observe. The manner in which Agassiz first taught a group of inquirers this interesting lesson, was an event to be remembered. It was in the open air. The question as to method was asked. Eggs were brought; the professor seated himself upon a convenient keg of nails, and the observers stood about him. He first showed in what position the egg should be held, and then with delicate and patient manipulation, he removed the shell in minute pieces at the right spot, and revealed the marvelous structure within, all the while accompanying his work with sparkling thoughts in delightful words. Another lesson was the constant and patient observation of the motions and habits of living specimens in the aquarium. Often a student would sit all day long watching a single specimen, and did not find such work either irksome, uninteresting or unprofitable. It has been remarked that the career of original investigation with Agassiz measurably closed soon after his coming to America, and his career as an instructor began. He turned his attention to the development of the natural history of America. This he saw clearly could not be done without the aid of trained naturalists, and there were none in America. It was then his mission to create them. The establishment of a complete museum, to which all students of natural history could have access, was the first step; a museum which should not only equal, but surpass the great museums of the Old World. The design, according to Agassiz’s own plan, was so far completed before his death, that what remained to be done could be as well done by his trained assistants. He had stamped his own character and ideas upon it indelibly. Prof. Tyndall declared that there was nothing like it in the Old World. Another equally qualified to judge, familiar with all the Old World museums, declared that nowhere in his travels had he seen such an amount of original work done as here. The museum at Cambridge is an institution peculiarly American in that it is arranged without the trammels of Old World methods. In it every specimen is labeled with the name, locality, date and donor securely fastened to it, and the same duly recorded. A specimen concerning which, from whatever cause, any uncertainty has arisen as to the locality, is rejected, and consigned to the laboratory for dissection, only the best attainable specimens are retained. Unnecessary or imperfect duplicates are set aside for study or exchange. His completed plan will present a collection of the animals of the world arranged systematically, according to the principle of classification adopted by Agassiz, and exhibiting their structure. This is supplemented by minor collections showing embryonic development of the different types of animal life, synthetic relations, etc.