2-48 The Unity of the Organism 



"intelligence," or many another indispensable term. 



Our inquiry is not as to whether there are such things as 

 instincts, but how they operate and what they signify for 

 the animals possessing them. Perhaps of highest interest 

 to us is the fact that innumerable instincts, if indeed not all, 

 are as indubitably hereditary as are any animal endowments 

 whatever. This comes out especially convincingly in those 

 numberless cases where the instinctive operations develop 

 strictly part passu with the anatomical development of the 

 young, there being absolutely no opportunity for them to 

 learn, even subconsciously. 



Take as an example the crustacean Amphithoe longimana, 

 in which Holmes compared in detail the activities of the 

 newly hatched young with those of the adult. "Amphithoe 

 lives in tubular nests which are usually lodged among sea 

 weed. The nests are somewhat longer than the animal, 

 and are spun of a web-like material into which bits of sea 

 weed are often incorporated which help to conceal the oc- 

 cupant. In its nest Amphithoe lies in wait for prey, ready 

 to dart out upon any small creature which touches the ends 

 of its long antennae. 



"The activities of the adult Amphithoe, with the exc\p- 

 tion of those concerned in reproduction, are almost ex- 

 actly paralleled by those of the young. I have taken the 

 eggs from the maternal brood pouch shortly before hatch- 

 ing and kept them isolated in individual dishes. For some 

 time after emerging from the egg the young were weak and 

 had imperfect control of their movements, which were jerky 

 and irregular. Soon the minute creatures would crawl and 

 swim much like the adults, and the next day they began 

 constructing nests which were the same shape as those formed 

 by their parents." Then comes a part of the description 

 to which the reader's special attention is called because it 

 brings out, partly by implication, a richness of detail in be- 

 havior which defies full expression, and which every care- 



