THE EVOLUTION OF PLANTS. 
with and without awns, and among them, strange to say, a marked 
tendency is to be observed of approach to the forms derived from' 
T. Spclta. 
4. — Hybrids that are more fertile than either parent : Senecio Tussi- 
laginis ? x cnientus—ovfn experience ; Senecio cruentus 2 x Tussi- 
laginus — own experience ; Burbidge, Propagation and Improvement 
of Cultivated Plants," instances, hybrids of Calceolaria, Erica, Dianthus,. 
Pisum. 
5. — Quite sterile hybrids : Begonia * Gloire de Lorraine ' [B. socotrana 
X B. Dregei) — voucher, Mons. E. Lemoine ; Begonia ' Gloire de Seaux " 
{B. socotrana x B. subpeltata) — voucher, Mons. E. Lemoine; Dianthus 
eminens (D. aljoinus x deltoides) — Mr. Lindsay; Dianthus Lindsayt 
(D. alinnus x barbatus) — Mr. Lindsay ; Delphinium MacNabianum 
{D.nudicaule x cashmirianum)—Mx. Lindsay; Phlox lilacina (P.fron- 
dosa X Nelsoni) — Mr. Lindsay ; Rhododendron Lindsayi (B. DalhousicR- 
X Gibsoni) — Mr. Lindsay ; Rhododendron, unnamed {R. ciliatum: 
xEdgworthi) — Mr. Lindsay ; Syringa *La Lorraine ' (S. persica laciniata 
X vulgaris fl. ijI.) — Mons. E. Lemoine ; Syringa varina duplex 
[S. per sic a laciniata x vulgaris fl. pi.) — Mons. E. Lemoine. 
6. — Hybrids the descendants of which return to the parent species. 
Several authorities remark that reversions are characteristic rather of 
crosses than hybrids. Bailey says, in " Plant Breeding," p. 251, quoting' 
from Focke : The nearer the parent forms are related to each other, the- 
progeny of crosses show complete return to the parent forms." It is- 
curious, considering the belief some have in a general tendency to rever- 
sion, that under this head I have found it difficult to get authenticated 
examples. 
Cucumis Melo x trigonus. — According to Naudin the descendants, of 
this hybrid revert to one or other of the parents. 
Dianthus superbus x D. sinensis. — Mons. P. de Vilmorin writes r 
" Two years ago we pollinated D. superbus by D. sinensis. The first 
year the plants grown from seed gave a perfect hybrid, a perennial with 
thick straight stems like the D. superbus, and large flowered like the 
D. sinensis. But this year (second generation) almost all the plants are 
reverted to D. sinensis and are annuals. As you know it is generally at 
the second generation that the greatest difference between plants coming: 
from the same fecundation is to be observed." 
Primula. — Messrs. Sutton & Sons write : " We have occasionally- 
obtained fertile crosses between P. sinensis &nd. P. floribunda, P. obconica,. 
and P. sinensis, and P. Auricula with P. sinensis, but the progeny, 
though different in some respects from the female parent, was most like- 
it, and its seed produced plants which showed no distinction at all from 
the original female parent." 
Wheats. — Hybrids of Triticuni polonicuni and T. tiirgidum have 
been said to revert, and I am informed by Mons. E. Lemoine that the late 
M. Godron, director of the Botanic Gardens at Nancy, was of opinion 
that Wheats do revert. I am not aware of the particular cases in 
question, but observations by Mons. H. Vilmorin, so far as I know thenu 
appear to indicate the contrary. 
7. — Wild hybrids. 
