382 Boi/al Society : — 



My operations of cross-circulatiou (which I call *■) put me in pos- 

 session of three excellent silver-grey bucks, four excellent silver-grey 

 does, and one doe whose operation was not successful enough for me 

 to care to count it. One of my x does (B) had already undergone 

 the operation u, and I had another of my old lot (C (m)), which I 

 left untouched. There were also three common rabbits, bucks, which 

 were blood-mates to silver-greys, and four common rabbits, does, 

 also blood-mates of silver-greys. From this large stock I have 

 bred eighty-eight rabbits in thirteen litters, and in no single case 

 has there been any evidence of alteration of breed. There has been 

 one instance of a sandy Himalaya; but the owner of this breed 

 assures me they are liable to throw them, and, as a matter of fact, 

 as I have already stated, one of the does he sent me, did litter and 

 throw one a few days after she reached me. The conclusion from 

 this large series of experiments is not to be avoided, that the doctrine 

 of Pangenesis, pure and simple, as I have interpreted it, is in- 

 correct. 



Let us consider what were the alternatives before us. It seems h 

 priori that, if the reproductive elements do not depend on the body 

 and blood together, they must reside either in the solid structure 

 of the gland, whence they are set free by an ordinary process of 

 growth, the blood merely affording nutriment to that growth, or 

 else that they reside in the blood itself. My experiments show that 

 they are not independent residents in the blood, in the way that 

 Pangenesis asserts ; but they prove nothing against the possibility 

 of their being temporary inhabitants of it, given off by existing cells, 

 either in a fully developed state or else in one so rudimentary that 

 we could only ascertain their existence by inference. In this latter 

 case, the transfused gemmules would have perished, just like the 

 blood-corpuscles, long before the period had elapsed when the ani- 

 mals had recovered from the operations. 



I trust that those who may verify my results will turn their atten- 

 tionto the latter possibility, and will try to get the male rabbits to 

 couple immediately, and on successive days, after they have been 

 operated on. This might be accomplished if there were does at hand 

 ready to take them ; because it often happens that when the rabbits 

 are released from the operating-table, they are little, if at all, dashed 

 in their spirits ; they play, sniff about, are ready to fight, and, I have 

 no doubt, to couple. Whether after their wounds had begun to in- 

 flame, they would still take to the does, I cannot say ; but they 

 sometimes remain so brisk, that it is probable that in those cases 

 they would do so. If this experiment succeeded, it would partly 

 confirm the very doubtful case of the pied young of the doe which 

 died after an operation of cross-circulation (which, however, further 

 implies that though the ovum was detached, it was still possible 

 for the mother gemmules to influence it), and it would prove that 

 the reproductive elements were drawn from the blood, but that they 

 had only a transient existence in it, and were continually renewed 

 by fresh arrivals derived from the framework of the body. It would 

 be exceedingly instructive, supposing the experiment to give afiirma- 



