334 SIRKS, PRAE-MENDELISTISCHE ERFELIJKHEIDSTHEORIEEN. 
waar DE VRIES zich ten opzichte der erfelijkheid vrijwel geheel 
aan de zijde van WEISMANN plaatst. 
Principieeler erfelijkheidstheorie dan de intracellulaire pangenesis, 
was reeds jaren tevoren, ongeveer tegelijk met DARWIN, gegeven 
door GALTON, en hij was dan ook eigenlijk de eerste belangrijke 
tegenstander der darwinistische pangenesishypothese. GALTON zag 
onmiddellijk de groote moeilijkheden, die de transporthypothese ople- 
verde. Hij begon met enkele proefnemingen in elkaar te zetten, die de al 
of niet houdbaarheid dezer veronderstelling moesten kunnen aan- 
toonen. In zijn autobiographie vertelt hij daarover: „According to 
Darwın’s theory, every element of the body throws off gemmules, 
each of which can reproduce itself, and a combination of these 
gemmules forms a sexual element. If so, I argued, the blood which 
conveys these gemmules to the places where they are developed, 
whether to repair an injured part or to the sexual organs, must 
be full of them. They would presumably live in the blood for a 
considerable time. Therefore if the blood of an animal of one species 
were largely replaced by that of another, some effect ought to be 
produced on its subsequent offspring. For example, the dash of 
bull-dog tenacity that is now given to a breed of greyhounds by 
a single cross with a bull-dog, the first generation corresponding 
to a mulatto, the second to a quadroon, the third to an octoroon, 
and so on, might be given at once by transfusion. Bleeding is 
the simplest of operations, and I knew that transfusion had been 
performed ‚on a large scale; therefore I set about making minute 
inquiries”. 
„These took a long time, and required much consideration. At 
length I determined upon trying the experiment on the well-known 
breed of rabbits called silver greys, of which pure breeds were 
obtainable, and to exchange much of their blood for that of the 
common lop-eared rabbit; afterwards to breed from pairs of silver 
greys in each of which alien blood had been largely transfused. 
This was done in 1871 on a considerable scale. I soon succeeded 
in establishing a vigorous cross-circulation that lasted several 
minutes between rabbits of different breeds, as described in the 
Proceedings of the Royal Society, 1871. The experiment were tho- 
rough, and misfortunes very rare. It was astonishing to see how 
quickly the rabbits recovered after the effect of the anaesthetic had 
