FISHES. 47 



FISHES. 



Visitors who desire to inspect the exhibited series of Fishes 

 have to pass from the Bird-Gallery on the ground-floor by the 

 first corridor on the right-hand side into a large side Gallery, as 

 shown on the plan accompanying this Guide. The contents are 

 chiefly stuffed specimens * and skeletons ; the former arranged in 

 a continuous series in the Wall-cases numbered 1-44, the latter in 

 Table-cases marked A-G. Large objects are exhibited in special 

 cases, or placed on stands on the floor of the Gallery. 



GENERAL NOTES. 



The class of Fishes, of which now some 10,000 species are known, 

 exhibits a much greater amount of variation of external form, and 

 of diversity of their principal internal organs, than any of the 

 higher Vertebrates. But as all, without exception, live in the 

 water throughout life, they possess common distinctive characters 

 in those systems of their organization which are in direct relation 

 to their aquatic mode of life, viz. in the organs of respiration and 

 locomotion. 



Fishes, therefore, may be described as vertebrate animals living 

 in water, and breathing the air dissolved in the water by means of 

 gills or branchiae ; whose heart consists of two chambers only, viz. 

 a single veutricle and single atrium ; whose limbs, if present, are 

 modified into fins, supplemented by unpaired, median fins ; and 

 whose skin is either naked or covered with scales or osseous scutes 

 or bucklers. With few exceptions, Fishes are oviparous. 



* The collection of Fishes preserved in spirit is placed with other similar 

 preparations in a separate locality, such specimens being preserved to meet 

 the requirements of the scientific student, and generally unsuitable for 

 exhibition. 



