110 THE IIISTOliY OF ANIMALS. [B. V- 



nor singly, nor in every kind, as it does in most fish 

 which produce their young in the spring: nor do they 

 produce as many ova at other seasons. But it must 

 not escape our notice, that as different countries make a 

 great difference in plants and animals, not only in the habit 

 of their body, but also in the frequency of their sexual in- 

 tercourse and production of young; so different localities 

 make a great difference in fish, not only in their size, and 

 habit of their body, but in their young, and the frequency 

 or rarity of their sexual intercourse, and of their offspring 

 in this place or that. 



CHAPTER X. 



1. THE malacia breed in the spring, and first of all the marine 

 sepia, though this one breeds at all seasons. It produces 

 its ova in fifteen days. When the ova are extruded, the 

 male follows, and ejects his ink upon them, when they be- 

 come hard. They go about in pairs. The male is more 

 variegated than the female, and blacker on the back. The 

 sexes of the polypus unite in the winter, the young are pro- 

 duced in the spring, when these creatures conceal themselves 

 for two months. It produces an ovum like long hair, similar 

 to the fruit of the white poplar. The fecundity of this animal 

 is very great, for a great number of young are produced 

 from its ova. The male differs from the female in having a 

 longer head, and the part of the tentaculum which the fish- 

 ermen call the penis is white. It incubates upon the ova 

 it produces, so that it becomes out of condition, and is not 

 sought after at this season. 



2. The purpurae produce their ova in the spring, the 

 ceryx at the end of the winter; and, on the whole, the 

 testacea appear to contain ova in the spring and autumn, 

 except the eatable echini. These principally produce their 

 young at the same seasons, but they always contain some 

 ova, and especially at the full and new moon, and in fine 

 weather, but those which live in the Euripus of the Pyrrh&i 

 are better in winter. They are a small kind but full of ova. 

 All the cochleae appear to contain ova at the same season. 



CHAPTEH XI. 



1. THE undomesticated birds, as it was observed, generally 

 pair and breed once a-year. The swallows and eottyphuii 



