Natural History of their Generation. 329 



(3) It will be necessary to repeat this nianoeiivre twice a 

 week, or at least once a week ; and by paddling wiih your 

 wooden slice in all parts, vou will bring the water upon tha 

 eggs in motion ; for let the water be ever so clear, ihere 

 will adhere to the eggs in a few days a sublil filth, which 

 lavs the foundation for their corrnplion, even when the 

 lish is already alive in the egg ; therefore it is necessary to 

 clear theni bv this genile means. 



(4) After the eggs have been about three weeks in this stale, 

 one inav perceive through their hard skin a divided black 

 spot, which are the eve? of the young fish ; the body is too 

 transparent to be seen with the naked eye ; but after four 

 weeks, if you squeeze one of the cgrrs between your tinkers, 

 you will see the fi^h make a motion, and turn within, then 

 you may perceive his form. At last, alter lying five weeks 

 in this state, and under a continual current of running 

 water, the young fishes will bore their heads through 

 the shell of the eggs ; and by movinc with their bodies 

 will, in about halt an hour, free themselves entirely from 

 the shell, with the yolk of the mother egg hanging to ■ 

 their bellies like a small bag. When they are out ot the 

 egg, thcv will lie still in the cavities between the gravel, 

 and have then the appearances as if the head of a pin were 

 fastened to a reddish field-pea, en account of these hanging 

 bags: for tlirce or four weeks they receive their nourish- 

 ment from the substance contained in this bag, til! by de- 

 grees, as the fishes grow larger, the bags disappear; then 

 they besiin gradually to assume the shape of fishes, and 

 hiving no further sustenance from this bag, they will seek 

 for foud themselves. But as in so small a compass as this 

 breeding- trough there cannot be a sufficient quantity of 

 small insects to be found for their sustenance, thev seek 

 for room, where they may meet With them m greater abun- 

 dance ; they then follow the current ot the v\aler, and slip 

 through tlie brass grate at the end of the box, where yoa 

 should have a larger wooilen box like a brewer's cooler, or 

 a small clean fish-pond, covered with gravel to receive 

 them ; in which they will grow in about six months con- 

 siderably. 



§V. 



To instruct my readers as much as possible, I shall add 



several observations of the formation of these vmuif trouts. 



(1) After an egg has been impregnated by the sperm of 



the male (which is riirough an invisible opening into it), it 



lodges in the while li(iuor under the shell, aiul round the 



yulk. 



