148 Salmon at the Antipodes. 



from this cross having been proved to be 

 fertile. 



There are certain characters which are 

 found to be constant in numbers of individuals, 

 and which are relied upon for identification of 

 the species. These are : — the form of the 

 bones of the cheek and jaws ; the size, arrange- 

 ment, and permanence, or otherwise, of the 

 teeth ; the form and development of the fins ; 

 the size of the scales indicated by the number 

 of rows above and below the lateral line ; the 

 number of the vertebrae, and of the pyloric 

 caeca, which are sac-like appendages to the 

 main gut, which is short and simple. 



There are other characters, which are found 

 to be variable, and little reliable as a means of 

 identifying the species, such as the number 

 of the fin rays ; the colour, form, size, number, 

 and position of spots and bars, or parr-marks. 

 Although the parr-marks, or transverse bars, 

 are common to all the individual species of 

 the genus, it has been observed that the 

 migratory species have two or three more 

 than the non-migratory kinds. The males 

 attain brighter colours than the females as 

 the spawning season approaches, while the 



