ROTIFERA 



employment for many of the in- 

 habitants. In the Middle Ages the 

 family of Lacy built a castle here. 

 Pop. (1921), 15,249. 



Rotifera (Lat. rota, wheel ; ferre, 

 to bear). Large group of aquatic 

 animalcules. It is regarded by 

 some zoological authorities as con- 

 stituting a separate phylum of the 

 animal kingdom, and by others as 

 a class of the annelid worms. The 

 rapid movements of the cilia which 

 surround the fore part of the body, 

 when examined under a micro- 

 scope, have the appearance of a 

 revolving wheel. They are all ex- 

 tremely small the largest being 

 just visible to the naked eye and 

 they are very abundant in ponds, 

 while a few species inhabit the sea. 

 Some of them are fixed by stems 

 to objects, and others swim freely. 

 They consist of a body terminated 

 anteriorly by a ciliated disk and 

 posteriorly by a foot for attach- 

 ment or a tail-like outgrowth. The 

 transparency of the body usually 

 allows the internal organs to be 

 well seen. The alimentary canal 

 consists of a tube passing to an 

 anal aperture at the hinder end of 

 the body, and it is partly armed 

 with minute teeth which serve the 

 purpose of crushing the food which 

 has been brought to the mouth by 

 the action of the ring of cilia. Their 

 food consists of still more minute 

 organisms and particles of vege- 

 table matter. 



The body cavity is filled with 

 fluid in which the organs float, 

 being more or less loosely attached 

 by cells of connective tissue. In 

 some species part of the oesophagus 

 can be everted and the teeth 

 brought to bear upon the algae on 

 which the animal browses. There 

 appears to be no definite respiratory 

 system, but the organs are aerated 

 by the diffusion of water through 

 the body wall and its subsequent 

 expulsion from a kind of bladder. 

 It is remarkable that so lowly an 

 organism should possess a bilobed 

 brain, which often bears eyes. The 

 sexes are separate, and the young_ 

 are produced from eggs. In some 

 species eggs are apparently pro- 

 duced parthenogenetically in the 

 summer months, and these are of 

 two kinds larger ones from which 

 females are hatched, and small ones 

 which result in males. In autumn 

 the sexes pair and another type 

 of eggs is produced. These have a 

 thick shell and do not hatch out 

 till the following spring. 



About 700 species of rotifers are 

 known, and several of them may 

 usually be found by searching the 

 weeds from any clear pond. They 

 form very interesting objects for 

 examination under the microscope, 

 and some of their main features can 



67 1 9 



be made out with a good pocket lens. 

 Onespecies,Jfe/jV!ertonn</ew,builds 

 a tube of minute balls of clay or of 

 other matter that may be held in 

 suspension in the water. Rotifers 

 are grouped into four classes 

 those that live in tubes, those that 

 creep like a leech, those that swim 

 freely, and those that progress by 

 leaps. See Animal ; consult also 

 The Rotifera, C. T. Hudson and 

 P. H. Gosse, 1886; Rotifera, M. 

 Hartog, Cambridge Natural His- 

 tory, vol. ii, 1896. 



Rotomohana. Lake of N. 

 Island, New Zealand. On its 

 shores, previous to 1886, were hot 

 springs and terraces of siliceous 

 sinter of brilliant colour, the most 

 beautiful of their kind in the world. 

 The terraces were destroyed by 

 an eruption of Alt. Tarawera in 

 1886, and the lake is now a deep 

 crater 2 sq. m. in area, in which a 

 new warm lake has formed. 



Rotorua. Lake of N. Island, 

 New Zealand. Of volcanic origin, 

 it is 20 m. from Alt. Tarawera, in 

 the thermal spring region. 



Rotorua. Township of N. 

 Island, New Zealand. Near the 

 lake of the same name, it is 171 m. 

 by rail from Auck- * 

 land, in the midst 

 of the 150 m. \ 

 stretch of country 

 of geysers, hot and 

 cold lakes, fuma- 

 roles, etc., which 

 make it one of the 

 most wonderful 

 natural features 

 of the world. A 

 Alaori centre, it 

 is owned and 

 managed by the 

 state as a health and tourist resort, 

 and within reach are facilities for 

 fishing, deer stalking, and shooting 

 of many kinds. Pop. 2,800. 



Rotrou, JEAN DE (1609-50). 

 French dramatist. The most im- 

 portant of the older contempor- 

 aries of Corneille, he was born at 

 Dreux in Normandy, Aug. 21, 1609, 

 and educated there and in Paris. 

 He began by writing plays for 

 various companies of actors ; was 

 for a time one of the five poets em- 

 ployed by Richelieu to carry out 

 his dramatic ideas ; and died, June 

 28, 1650, of the plague in Dreux, 

 whither he went on learning that 

 the mayor had fled from his post. 

 His best work is to be found hi his 

 tragedies Saint-Genest and Vences- 

 las. See Jean Rotrou, W. Sporon, 

 1894 ; Rotrou, T. F. Crane, 1907. 



Rotten Borough. Popular 

 name given, in the early decades of 

 the 19th century, to those English 

 boroughs which, with populations 

 reduced to a handful, retained the 

 right of returning members to Par 



ROTTERDAM 



liament. This anomaly, with many 

 other abuses, was swept away by the 

 Reform Act of 1832. See Borough ; 

 Commons, House of ; Reform Act. 



Rottenburg. Town of Wurt- 

 temberg, Germany. It stands on 

 the Neckar, which separates it 

 from the suburb of Ehingen, 6 m. 

 S.W. of Tubingen. The buildings 

 include the church of S. Martin 

 and the Bishopshof, formerly a 

 Jesuit convent. The latter houses 

 a museum, while another building 

 contains a valuable collection of 

 Roman antiquities found on the 

 site of the Roman station of Sumelo- 

 cenna. Around is an important 

 hop-growing dist., and there are 

 woollen and spinning factories and 

 breweries. It was added to Wurt- 

 temberg in 1805. Pop. 8,000. 



Rotten Row. London riding 

 track, in Hyde Park (q.v.). It runs 

 W. from Hyde Park Corner to 

 Coal brook dale Gate, and returns E. 

 on the N. side of the carriage drive 

 between Albert Gate and Alexan- 

 dra Gate. The name is derived from 

 the soft layer of tan which forms 

 the surface, or, more probably, from 

 route du Roi, a road kept sacred to 

 royalty. 



Rotorua, New Zealand. Bath buildings at the Spa 



Rottenstone. Name given to a 

 porous, friable, siliceous rock used 

 largely for cleaning and polishing 

 steel, brass, and other metals, and 

 wood. The rock consists mainly of 

 aluminium silicate and carbona- 

 ceous matter, and is a decomposed 

 siliceous limestone. The best rot- 

 tenstone is found in Derbyshire 

 and S. Wales. 



Rotterdam. City and seaport 

 of the Netherlands, in the prov. of 

 S. Holland. It lies on the branch 

 of the Rhine delta known as the 

 Alaas, joined here by a small river, 

 the Rotte, and is 17 m. by rly. E. 

 of the Hook of 

 Holland, and 

 52 m. by rly. 

 S.S.W. of Amster- 

 dam. The main 

 part of the tcwn, 

 intersected b y 

 many quays and 

 Rotterdam arms canals, is on 

 the right bank ; opposite the long 

 quay called the Boompjes lies the 

 North Island, and the suburb of 



