THE ORCHID REVIEW. 19 
ZYGOPETALUM CROSSED WITH ODONTOGLOSSUM. 
AT the Royal Horticultural Society’s meeting on December 15th, 1896, 
Messrs. Heath & Son, of Cheltenham, exhibited ‘a hybrid seedling 
obtained by crossing Zygopetalum Mackayi with the pollen of Odontoglossum, 
which resembled the mother plant with the exception that the lip was slightly 
wavy and pure white, with some slight purple marks at the base and 
centre ”’ (supra, v., p. 32).. Plants have recently passed into the collection 
of W. Thompson, Esq., Walton Grange, Stone, and three spikes are now 
sent by Mr. Stevens. On examining these flowers, we fail to find any 
characters that can be clearly traced to the Odontoglossum parentage, but 
if all three have the same origin, it is quite clear that some modifying 
agency has been at work. One seedling is much like Z. intermedium 
(which, by the way, often does duty as Z. Mackayi in collections, and which 
in the present case we strongly suspect was the seed parent), but the other 
two are markedly different, having a narrower, wavy, white lip, with rows of 
elongated spots on the nerves, except at the margin. The first-named is 
strongly striped with purple right to the margin. We should like to see 
flowers from the actual plant which produced the seed, for there is some- 
thing mysterious in this so-called hybrid, which has previously behaved in 
the same way with Messrs. Veitch, as has several times been mentioned in 
our pages. The presumption is that it is a case of hybridity where the 
Zygopetalum parent obtains such a preponderating influence as to almost 
obliterate all trace of the Odontoglossum. But if this is the case, the 
hybrid should be again crossed with the Odontoglossum, to see whether ~ 
some of the Zygopetalum influence cannot be eliminated. This experiment 
_ would be well worth following up. Again, Zygopetalum has been used as 
the seed parent, but we would suggest that the cross should be reversed. 
If anything like a similar result could be obtained by making Odontoglossum 
the seed bearer, the evidence would be conclusive. A suggestion formerly 
made, that the pollen of the Odontoglossum might in some way stimulate 
the development of the ovules without fertilisation being effected, is rather 
disproved by the evidence now to hand, for this would be a case of 
parthenogenesis, or budding of the ovules, and it is known that plants 
obtained by vegetative reproduction do not vary. The decorative value of 
this useful old Orchid is too well known to require mention, but the 
interest attached to the solution of this curious problem is such that we 
hope to see further experiments carried out. The Zygopetalum might be 
crossed with several different genera, and the crosses reversed, when the 
result could not fail to be interesting. 
