XXIV INTRODUCTION. 



British examples. Pennant says of the River Bullhead, 

 " It deposits its spaAvn in a hole it forms in the gravel, and 

 quits it with great reluctance ;" I have also been favoured 

 by an excellent observer with the following notice on the 

 same fish : — " It evinces a sort of parental affection for its 

 ova, as a bird for its nest, returning quickly to the spot, and 

 being unwilling to quit it when disturbed." It is believed 

 also of the Lump Sucker, that the male fish keeps watch over 

 the deposited ova, and guards it from every foe with the 

 utmost courage. If driven from the spot by man, he does 

 not go far, but is continually looking back, and in a short 

 time returns. 



A few observations on the impregnated roe may be worthy 

 attention. Dr. Walker of Edinburgh, in an essay on the 

 Natural History of the Salmon, published in the Transac- 

 tions of the Highland Society, quoting the experiments of 

 Jacobi of Berlin, says, he found that when the spawn of both 

 sexes were extracted from dead fishes, the ova by mixture 

 can be fecundated by the milt ; and when placed under water 

 in a proper situation can be brought forth into life. He 

 further discovered that this artificial fecundation can be ac- 

 complished with the roe and milt of fishes which have been 

 dead two and even three days. This appears to point out 

 the mode of obtaining the fishes of neighbouring countries 

 by the transportation as far as possible of the living gravid 

 fishes, afterwards for a time while dead, and finally by the 

 mixture and further transportation of the mixed roes. 



But there appear to be other, and still greater facilities. 

 Mr. Jesse states, that he has been assured by persons who 

 have lived many years in the East Indies, that ponds which 

 become perfectly dry, and the mud hard, have after the rainy 

 season been found with fish in them, although no stream 

 communicated with them, or any passage or other means by 



