THE INVERTEBRATE COURSE. 115 



in separate finger bowls in order that a named collection of liv- 

 ing animals be at hand for closer inspection than is possible in the 

 field ; later only the rarer animals are demonstrated. The course 

 possesses a named collection of the common molluscs of the re- 

 gion and is accumulating preserved collections of other groups. 



With the exception of the afternoons on Plankton and Protozoa, 

 little attempt is made to identify for class purposes the nearly 

 microscopic animaJs that may be taken, since it is the purpose of 

 the trips to acquaint the students with the larger, more outstand- 

 ing members of the local fauna. Doubtless we pass over more 

 species than are recorded. The field collecting has given a num- 

 ber of new records for this well-worked region, has yielded ma- 

 terial for one study of regional and seasonal distribution, 1 -and is 

 the basis for a study of the littoral ecology of Woods Hole now in 

 preparation. 



In earlier clays and again for the last eight years a catalogue 

 record of species taken has been kept and is on record as a part of 

 the library of the Laboratory. The person in charge of this com- 

 pilation is frequently called on to suggest to investigators avail- 

 able material suitable for certain investigations, or the where- 

 abouts of animals not usually collected by the supply department. 



Near the end of the course the field work is summarized in an 

 evening lecture on the ecology of the region, illustrated by slides 

 obtained from the American Museum of Natural History and by 

 projections of living animals. 



The students have the advantage of the bi-weekly evening lec- 

 tures maintained by the Laboratory; in addition, special lectures 

 directly related to the work of the course are arranged for the 

 benefit of the class. These are usually given on Saturday morn- 

 ing before the field trip for the day, or in the evening, and they 

 not only convey the information, but introduce the class to some of 

 the interesting personalities among the research group. In 1920 

 these special lectures were given : 



" Some Aspects of Physical Organization of Protoplasm," by 

 Robert Chambers. 



i Alice, W. C., " Note on Animal Distribution Following a Hard Winter," 

 BIOL. BULL., 36, pp. 96104. 



