r891.] Are Acquired Variatious Inherited ? 215 
and not self-acquired. I believe that no indisputable evidence for 
the inheritance of acquired characters has been produced under 
this head. . 
Another class of evidence consists in what are believed to be 
cases of the inheritance of maternal influences upon offspring 7 
utero. It is an axiom among breeders that an ill-bred sire may 
affect all future strains. One of the most striking cases is that of 
Lord Morton’s Arabian mare, which was sired by a Quagga, and 
later by a pure Arab, the foal of the latter showing zebra-like 
markings. Professor Turner says of this case: “I believe that 
the mother had acquired during her long gestation with the hybrid 
the power of transmitting quagga-like markings. The ova must 
have been modified while still in the ovary.” 
I refer to papers of Vines ” and Turner ® as bearing especially 
upon the supposed isolation of the germ-cells, and showing that 
in the lower Metazoa and some of the higher Metaphyta the 
germ-plasm is diffused through’the organism, and thus related to 
the soma. 
We should find in these transitional organisms, as I have 
suggested under Query I, that the relation between the somatic 
and germ-cells was established, if it exists. It is a necessary 
deduction from Weismann’s theory that if this relation was advan- 
tageous it must have been preserved by Selection. If Selection 
can bear the burden of Evolution, it certainly can account for the 
origin of the Lamarckian principle in inheritance. 
Conclusions—The conclusions we reach in this discussion 
must finally turn upon the existence of definite lines of blasto- 
genic variation. If there are no such lines, the Lamarckian 
principle falls ipso facto; if there are, we have still to estimate 
the probabilities between Weismann’s and Lamarck’s- principles 
as affording the most adequate explanation for them, keeping in 
mind the problem of Inheritance as affecting these probabilities. 
The Weismann principle depends upon Selection as the source 
See Nature, 1889, p. 532. 
e1 “ An Examination of Some Points in Prof. Weismann’s Theory of Heredity.” Nature, 
October 24th, 1889, p. 62. 
68“ The Cell Theory, Past and Present.” Nature. November 6th and 13th, 1890. 
