THE DRAMA OF LIFE 25 



tubes which become disconnected. The elongation is due 

 to internal fluid pressure and is always preceded and accom- 

 panied by a rise of pressure in the fluid of the body-cavity. 

 A lobster of considerable size may be bound hand and foot 

 with these threads of the ' cotton spinners ', as some 

 of the Holothuiians are called, a quaint instance of an 

 animal with a highly developed nervous system being 

 ensnared by the retaliations of a creature which has not 

 a ganghon or nerve-centre in its whole body. How dim 

 its awareness of the situation must be ! 



As Dr. Theodore Gill observes, the capture of fishes by 

 a lure began long before man acquired that art, it was 

 evolved among fishes themselves. The angler {Lofhius 

 fiscatorius) has a dorsal fin-ray turned into a rod and Kne 

 and danghng bait. ' It needs no hook, for the bait 

 attracts a victim sufficiently near to be seized upon by the 

 sudden leap of the angler '. The dangling of the bait is 

 quite automatic, and the device probably began fortuitously, 

 but the angler is very alert. In some Deep-Sea anglers there 

 is, in addition to wormhke baits, a phosphorescent bulb 

 or lantern which is perhaps seductive. 



Many butterflies, especially from warm countries, have 

 the power of exhaling a repulsive odour. Dr. F. A. Dixey 

 mentions Acraea, Euploea, and Papilio as genera among 

 which this property is common. ' Musty straw, stable 

 litter, rabbit-hutches, acetylene, bilge-water, these are some 

 of the substances to which the odours of these unsavoury 

 butterflies have been compared '. The odour may be 

 distributed from patches of speciahzed scales or hairs, or 

 from the general wing surface, but never from plume-scales 

 such as distribute the deHcate flower-like perfumes. More- 

 over the scents occur in both sexes and may be stronger 



