332 On Breeding of Fish, a?id ihe 



sides together ; and this happens \vhen two animalcnlse of 

 the sperm cnltT the egg in a diredt line, 90 degrees from 

 one another. 



(14) I have seen only one of these douhle fishes, where 

 the backs were across nearest the tail in a direct angle, so 

 that this fish formed a kind of a cross. This happens when 

 two aninialculae enter one egg, and are placed opposite each 

 other from their direct line to po degrees. These monsters 

 (lO, 13) were grown together from the head to the opening 

 of the belly, and that (14) had in some degree a joint 

 body ; but the backs were distinguisiied one from an- 

 other. 



(15) All these kinds of monstrons prodnctions die in 

 four or five weeks after ilieir common bag, or bcliv, is emp- 

 tied ; for as each head endeavours to follow its own direc- 

 tion in pursuit of foi)d, and both hinder each other, nei- 

 ther of them is capable to perforrn its intention ; so it is 

 impossible that either head can receive its proper nourish- 



^Mient, therefore they both must starve. 



(16) All monstrous productions \i\ the human and other 

 animal creations, which have a joint stomach, are produced 

 wlien an egg is impregnated by more than one spermatic 

 animalcula. ^ 



(17) All observations made on the trout, and its artificial 

 method of breeding, hold good with regard to salmon. 



Signed, S. L. Jacobi. 



Directions for Breeding Salmon, Trout, Cra?/-Fish, &c. 



Neither the form nor any particular kind of 'materials 

 are essential for the troughs ; but the following seem to be 

 most eligible : oak of two inches thick, twelve feet lonsr,. 

 one foot ten inches wide, and thirteen inches deep on the 

 outside ; the top divided into four parts. 



Spring- water out of rocks or stony gwund is the pro- 

 perest for breeding trouts and salmon ; but where it is not 

 ■ 10 be had, any other spring will do, provided the current is 

 strong enough to prevent its freezing in hard frosty weather. 

 If the spring has not fall: enough, you must raise a dam 

 round it, al least & foot higher then" the top of your trough ; 

 convey the wjtcr from t^hencc through a pipe or gutter to 

 the first g'-ale m the opening on the head of the trough 

 of an inch and half diameter, and let the fall from the ffrate 

 from the end of the pipe or gutter he two or three inches ; 

 the remaining water of the spring can be drawn off side- 

 ways. If you are inclined to erect several troughs, yon 

 may cither put them by the side of one another, or at the 



end,. 



