Mr. F. Galton's Experhnents in Pangenesis. 375 



his body (say "6 oz ) that 2 lbs. bears to the weight of the body of a 

 man (say 1.54 lbs.); and the same amomit of partially defibrinized 

 blood, taken from a killed animal of another variety, was thrown in 

 in its place. The blood was obtained 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 defibrinized blood, which I procured by whipping it up 

 thoroughly with a whisk of rice-straw ; and, in order to procure 

 suflScient blood, I had on one occasion to kill three rabbits. I alter- 

 nately bled the silver-grey and injected, until in some cases a total 

 of more than 3 ounces had been taken out and the same quantity, 

 wholly defibrinized, had been thrown in. This proportion corresponds 

 to more than 6 lbs. of blood in the case of a man. 



(3) The third operation consisted in establishing a system of cross- 

 circulation between the carotid artery of a silver-grey and that of a 

 common rabbit. It was effected on the same principle as that de- 

 scribed by Addison and Morgan (Essay on Operation of Poisonous 

 Agents upon the Living Body. Longman & ('o., 1829), but with 

 more delicate apparatus and for a much longer period. The rabbits 

 were placed breast to breast, in each other's arms, so that their throats 

 could be brought close together. A carotid of each was then ex- 

 posed ; the circulation in each vessel was temporarily stopped, above 

 and below, by spring holders ; the vessels were divided, and short 

 canulse, whose bores were larger than the bore of the artery in its 

 normal state, were pressed into the mechanically distended mouths 

 of the arteries ; the canulse were connected cross-wise ; the four spring 

 holders were released, and the carotid of either animal poured its 

 blood direct into the other. The operation was complicated, owing 

 to the number of instruments era])loyeil ; but I suspended them from 

 strings running over notched bars, with buttons as counterpoises, and 

 so avoided entanglement. These operations were exceedingly suc- 

 cessful ; the pulse bounded through the canulse with full force ; and 

 though, in most cases, it began to fall off after ten minutes or so, and 

 I was obliged to replace the holders, disconnect the canulse, extract 

 the clot from inside them with a miniature corkscrew, reconnect the 

 canulse, and reestablish the cross-flow two, three, or more times in 

 the course of a single operation, yet on two occasions the flow was 

 uninterrupted from beginning to end. The buck rabbit, which I 

 indicate by the letter O, was 37 1 minutes in the most free cross-cir- 

 culation imaginable with his " blood-mate," a large yellow rabbit. 

 There is no mistaking the quality of the circulation in a bared artery ; 

 for, when the flow is perfectly free, the pulse throbs and bounds 

 between the finger and thumb with a rush, of which the pulse at the 

 human wrist, felt in the ordinary way, gives an imperfect conception. 



These, then, are the three sorts of operations which I have per- 

 formed on the rabbits ; it is convenient that I should distinguish them 



