GRAND DIVISION, OR TYPE. VEEMES (THE WORMS). 



CHAPTER 1. 



THE RINGED WOItMS. 



The Various Sorts and Conditions of Worms Characters Classification ANNELIDA, THE RINGED WORMS 

 OLIGOCH^TA The Earth Worm -Characters Structural Peculiarities Habits Other Species The Naidse The 

 Tubificidze POLYCH^ETA Marine Worms Characters ERRANTIA ApHRoniTlD^: Sea Mice Scale Backs 

 The Eunicidie-The Sao Habits The Nereidse The White-rag Worm The Syllidas- The Phyllodocid;e THE TUBE- 

 MAKERS Characters The Lug Worm Habits "Baiters " on the Search CIRRATULIDJE Characters The Terebellidas 

 Their Larvaj The Serpulida; The Fan Sabella Serpula Vermicularis Its Array of Hooks -The ProtuLe and other 

 Tube-makers THE LEECHES Appearance Action of Sucker Characters Different Kinds The Horse Leech 

 The Glutton Aulostome* 



THE commonly received opinion about Worms is, that they are very unimportant animals which lead 

 very obscure lives, and that there are not many of them. But a little observation proves the fallacy 

 of the greater part of the popular idea. The common Earth Worm is seen in numbers early in the 

 morning, and on every lawn the birds may be noticed pulling them out of their holes and swallowing 

 them. Boys who require Worms for fish-bait soon become impressed with their numbers, for every 

 dig of the spade brings up one or more. By the sea-side, Lob Worms are forked out of the sand 

 by fishermen, in abundance. In chemists' shops one used to see quantities of leeches in pots, and 

 that they are Worms is pretty evident. Sometimes in out-of-the-way lecalities, the shop-windows 

 of worm-doctors are to be seen filled with bottles containing flat, long, limp-looking things, called 

 Tape Worms ; and every nurse knows that children suffer from Thread Worms. The farmer loses his 

 sheep from a curious head affection, and on examining them he finds peculiar Worms. Grouse and 

 Chickens die from the gapes, and it is a Worm that does it. Pigs suffer from a Worm in their 

 muscles, and fishes have others in their bodies and eyes, and man has them sometimes in his blood. 

 Finally, in the marine aquarium the loveliest fan-shaped expansions, coming out of tubes fixed 

 to the rock, are the breathing organs of a Worm. In numbers, probably the Worms surpass 

 all other things except the Infusoria ; in habits they are most varied, and they are correspond- 

 ingly diversely fashioned. In some Worms there is boldness and a power of roaming for 

 purposes of attack, and then they are well provided with structures and organs ; but in others there 

 is only a very passive existence, and there is an extraordinary absence of structures, senses, and 

 of many organs. Parasitism within animals is the lot of many Worms, and some lead a part of 

 their life in one animal, and another in a second \mwilling host, or they may live free at some time 

 or other. So varied are the shapes and so inconstant are many of the structures of the Worms, 

 that it is by no means easy to give a definition which shall include them all. Not only peculiar 

 structures, but also the absence of certain structures known to exist in other animals, have to be 

 considered. Thus it is found that an animal does not exactly correspond with one of the articulate 

 grcmps ; and another resembles in certain points, but not in all, an Infusorian. They are then 

 placed with the Vermes, because of the existence of certain fundamental structures. Again, many of 

 the Vermes are parasitic, and their structures have been most curiously modified to meet their method 

 of life or, rather, their methods for most pass through very remarkable life-cycles. 



The Vermes do not move by means of articulated limbs, and the body is not jointed like that 

 of a Crustacean or Insect. But whatever may be the shape of the body, it is composed of incomplete 

 segments, the majority of which are similar, and is more or less ringed outside. The segments are 

 provided with offensive and locomotive organs on both sides, and usually with a special excretory 

 organ opening from within. There is a water system communicating with a cavity in the body 

 surrounding the digestive system, and with the outside, called the perivisceral cavity. The digestive 

 system may be well developed, but in some parasites it is absent, and their nutrition takes place by 

 absorption through the outside of the body. There is a kind of circulatory system present in some, 

 and also special organs of respiration, such as branchial tufts ; but many are without them. The 

 nervous system may consist of a cord around the oesophagus, with ganglia above and below,, 

 and a ganglionic cord along the ventral surface within ; or the vestiges of the system may be very 

 scanty. Sense organs, such as eyes, may exist in a rudimentary condition, and also organs of feeling. 

 The digestive organs vary greatly in their development ; and the stomach and intestines, fairly de- 

 veloped in some, are wanting in others. The movements of the body are not produced by jointed* 



