APPENDIX 529 



about itself a silken cocoon. There, alone and in the dark- 

 ness, it spins a cocoon of finest silk, and deposits a chalky 

 white secretion in its meshes. Then the moth emerges and 

 seeks shelter, sitting with wings closelaid against the brown- 

 ish bark. Later, it seeks a mate. Every act of life is per- 

 formed without instruction or experience: such an act as 

 cocoon-spinning is performed but once in a lifetime, yet 

 perfectly performed. All acts are instinctive, and automatic. 

 There is no place or time for the education of the individual. 



Study 620,. Observations on the instincts of the tent-caterpillar. 

 This study, if undertaken in May when the caterpillars are 

 still in their nests, may utilize living material for nest rela- 

 tions. Boughs may be cut and taken to the laboratory, with 

 living larvae, nests, trails, and old egg clusters on them. The 

 feeding and silk spinning activities of the larvae may be 

 observed. Later stages and activities may be demonstrated 

 with preserved specimens of cocoons and pupae, and adult 

 moths of both sexes. A few moths should be seen mounted 

 upon a proper background to show their protective coloration 

 and attitudes. 



The record of this study may consist of an illustrated 

 account of the chief activities of the tent-caterpillar, as evi- 

 denced by the material provided : ( i ) freedom-seeking of the 

 larvae at hatching time; (2) foodseeking; (3) trail-laying; 

 (4) establishing of nest; (5) making of trails away from the 

 nest; (6) descent to the ground; (7) cocoon spinning ; (8) 

 transformation to pupae ; (9) emergence of adult ; (10) shelter 

 seeking; (n) mate seeking; (12) egg laying by the female. 

 The following diagrams at least should be included among the 

 illustrations : a section of egg cluster showing both eggs and 

 secretion; and outline of the nest in relation to branches, 

 twigs, trails, and egg cluster; a cocoon. Changes of bodily 

 form and of body-products (secretions) accompanying 

 changes of activities should be carefully noted. 



