XXIV INTRODUCTION. 



masses of fat, which are called soft roe ; they remain, how- 

 ever, firm till the actual season of spawning, when they be- 

 come by degrees more and more fluid, and the whole is ulti- 

 mately voided by small portions at a time under slight 

 abdominal pressure. 



A few exceptions to this rule appear to exist ; but which 

 may perhaps rather be considered malformation than natural 

 structure. According to Cavolini and Cuvier, some species of 

 the genus Serranus have each lobe of roe made up of a por- 

 tion of hard and of soft roe, and these fishes have been con- 

 sidered as hermaphrodites, each fish capable of producing 

 fertile ova without the assistance of a second fish. Among 



o 



other accidental malformations may be included the appear- 

 ance of a hard or female roe on one side, and a soft or 

 male roe on the other side of the same fish. This has 

 been observed occasionally in the Perch, Mackerel, Carp, 

 Cod, Whiting, and Sole ; and the probability is, that in 

 these cases the fishes are prolific alone, since the two 

 lobes of roe are observed to be of equal growth, advanc- 

 ing to maturity together. Pallas believed that in the ge- 

 nus Syngnathus there were no males ; but the singular 

 anomaly of both sexes being found to carry ova, the females 

 in the abdomen, and the males for a time in their caudal 

 pouch, is now understood. The supposed hermaphroditism 

 of the Lampreys has been disproved by various modern ob- 

 servers. 



At the season for depositing the spawn, which varies with 

 almost every genus, some species repair to the gravelly shal- 

 lows of rivers, and others to the sandy bays of the sea. 

 This movement is called by some fishermen, " going to hill, 

 or reading ;"" other species resort to bunches of weeds. In 

 many instances, when ready to deposit her spawn, a female is 

 accompanied by two males, one on each side, a provision of 

 nature which seems intended to secure the impregnation of the 



