APPENDIX 527 



Forms not figured will be identified by them and listed on the 

 blackboard. Take samples from top and bottom as well as 

 from the middle of the containers; for, on standing, certain 

 forms rise and get caught in the surface film, and others settle 

 with the bottom sediment. Hasten slowly. Distinguish 

 carefully. Credit for this work will be given in proportion to 

 the care and time spent in studying the plancton samples 

 provided. 



The record of this study will consist in an annotated list of 

 the forms found, together with simple diagrams of form of 

 parts that serve for recognition. List the forms by groups. 

 Notes on the individual forms should cover color (as indicat- 

 ing whether producer or consumer in plancton society), 

 relative abundance, size, activity, peculiarities of structure, 

 form and habits, stage found (when not adult) and any other 

 biological phenomena (as parasitism, epiphytism, etc.) that 

 may be observed. 



THE INSTINCTS OF THE TENT-CATERPILLAR 



(A supplementary study on instincts.) 



There are sequences of automatic activities manifest in the 

 lifetime of every animal, even man; and the shifts from one 

 kind of activity to another accompany growth and changes 

 of bodily states, and are always a part of an inherited educa- 

 tion that is, the common possession of all the members of a 

 species. The shifting program of instinct will be easily 

 followed in an insect like the tent-caterpillar (Clisiocampa 

 americana) which undergoes marked changes of form in its 

 lifetime, and is ushered into each new phase of its existence 

 fully equipped for doing everything necessary. 



The eggs are laid in mid-summer on twigs of wild cherry 

 and apple. The female moth makes no mistakes as to the 

 proper kind of trees for food for her young, altho she does not 



