396 



Mr. F. Galton's Experiments in Pangenesis. [Mar. 80, 



Serting and tying the canuloe, to making the cross-connexions, to recording 

 the quality of the pulse through the exposed arteries, and making the other 

 necessary notes. 



. The breed of rabbits which I endeavoured to mongrelize was the " Silver- 

 grey." I did so by infusing blood into their circulation, which I had pre- 

 viously drawn from other sorts of rabbits, such as I could, from time to 

 time, most readily procure. I need hardly describe Silver-grey rabbits 

 with minuteness. They are peculiar in appearance, owing to the intimate 

 mixture of black and grey hairs with which they are covered. They are 

 never blotched, except in the one peculiar way I shall shortly describe ; and 

 they have never lop ears. They are born quite black, and their hair begins 

 to turn grey when a few weeks old. The variations to which the breed is 

 liable, and which might at first be thought due to mongrelism, are white 

 tips to the nose and feet, and also a thin white streak down the forehead. 

 But these variations lead to no uncertainty, especially as the white streak 

 lessens or disappears, and the white tips become less marked, as the animal 

 grows up. Another variation is much more peculiar : it is the tendency 

 of some breeds to throw " Himalayas," or white rabbits with black tips. 

 From first to last I have not been troubled with white Himalayas ; but in 

 one of the two breeds which I have used, and which I keep carefully sepa- 

 rated from each other, there is a tendency to throw " sandy" Himalayas. 

 One of these was born a few days after I received the animals, before any 

 operation had been made upon them,. and put me on my guard. A similar 

 one has been born since an operation. Bearing these few well-marked ex- 

 ceptions in mind, the Silver-grey rabbit is excellently adapted for breeding- 

 experiments. If it is crossed with other rabbits, the offspring betray mon- 

 grelism in the highest degree, because any blotch of white or of colour, 

 which is not " Himalayan," is almost certainly due to mongrelism ; and so 

 also is any decided change in the shape of the ears. 



I shall speak in this memoir of litters connected with twenty silver- 

 grey rabbits, of which twelve are does and eight are bucks ; and eighteen of 

 them have been submitted to one or two of three sorts of operations. 

 These consisted of : — 



(1) Moderate transfusion of partially defibrinized blood. The silver- 

 grey was bled as much as he could easily bear ; that was to about an ounce, 

 a quantity which bears the same proportion to the weight of his body (say 

 76 oz.) that 2 lbs. bears to the weight of the body of a man (say 154 lbs.) ; 

 and the same amount of partially defibrinized blood, taken from a killed 

 animal of another variety, was thrown in in its place. The blood was ob- 

 tained from a yellow, common grey, or black and white rabbit, killed 

 by dividing the throat, and received in a warmed basin, where it was stirred 

 with a split stick to remove part of the fibrine. Then it was filtered 

 through linen into a measuring-glass, and thence drawn up with a syringe, 

 graduated into drachms ; and the quantity injected was noted. 



(2) The second set of operations consisted in a large transfusion of wholly 



