THE INVERTEBRATE COURSE. 101 



familiarize himself with the forms to be used in the laboratory 

 and with the general literature of the group, but he also spends 

 time studying the representatives found near Woods Hole so as to 

 be able to identify them in the field. He goes through the special 

 literature in order that he may be able to give intelligent informa- 

 tion on the points of unusual interest connected with the phylum, 

 particularly the research problems in which it has played or is 

 playing a part. 



The instructor in charge of the course determines who shall be 

 admitted to the course under the rules of the laboratory, super- 

 vises field work and has general oversight of the organization. 

 He takes his regular turn in lecture and laboratory along with 

 the other instructors. These are in turn individually responsible 

 for the organization and presentation of their particular groups. 

 Each instructor meets with the men who are to assist him, goes 

 over in detail the work planned, and for the time being has com- 

 plete charge of instruction. He is aided by " experience " cards 

 which set forth in some detail the results of past methods, but he 

 is not bound by tradition. 



The course ends on the second Tuesday in August and begins 

 six weeks earlier. This gives a total of thirty-six working days 

 which are divided as follows : 

 Course lectures, 29. 



Special lectures, two by staff members and a varying number of 

 invited lectures from Laboratory investigators. 



Laboratory periods, about 56. This number varies with the num- 

 ber of mid-week field trips taken. 



Field excursions, about nine. 



Holiday, the Fourth of July. 



The formal day begins at nine with an hour's lecture, usually 

 on the group to be studied in the laboratory period following. Al- 

 though it is difficult to generalize about the lecture methods, it is 

 common with the larger phyla to present schematically an ideal 

 representative of a given group, trace its phylogenetic develop- 

 ment, describe in detail special structures, or characteristic physi- 

 ological activities, and give the differentiations within the group 

 and their relation to the environment in which they are found. 



