<2 THE ORCHID REVIEW. [Maxcu, 1915. 
‘Bohnhofiz x Odm. Harryanum), all derived from the same seed pod, to 
illustrate the remarkable diversity in colour development among secondary 
‘hybrids, and as affording evidence of the altogether erratic behaviour of the 
‘colour-developing elements. In the majority the prevailing colour was 
‘dull dark purple, in some cases with more or less whitish tint between the 
blotches, but in others the ground was yellow, with browner blotches. 
There was also much variation in the colour of the lip, and in the shape of 
‘the segments. 
These flowers were also exhibited by Mr. Gurney Wilson at the meeting 
of the Scientific Committee, as illustrating phenomena of colour distribution 
that were extremely common among secondary hybrids, and it was quite 
‘evident that other problems were involved. 
THE MUTATION THEORY.—A paper, entitled ‘‘Some fundamental morpho- 
logical objections to the Mutation Theory of De Vriese,” appears in the 
January issue of the American Naturalist (pp. 5-21), which has some interest 
for lovers of Orchids. The chief foundation of the theory was furnished by 
the conduct of CEnothera Lamarckiana, which under cultivation gave rise 
constant and had all the attributes of species. The view was soon 
advanced that these “ Mutants” were the products of hybridity, and that 
{Enothera Lamarckiana was a hybrid, further evidence of which was to be 
found in the fact that about one-third of its pollen was abortive. The 
phenomena of mutation have since been observed in other species of 
(Enothera, and Prof. Jeffrey advances the view that not only is the genus 
generally characterised by genetically impure or hybrid species, but that 
the condition of genetic impurity is extremely common in the Onagracee 
as a whole—a view supported by a number of observations and photographs. 
He remarks that unusual variability is ordinarily regarded as prima facté 
evidence of hybridism, and recalls the fact that hybridisation is one of 
the commonest expedients adopted by the practical breeder for. breaking 
up the continuity of the germ plasm. He then remarks that hybridism 
is a commonly recognised feature among flowering plants, and work carried 
on in the Harvard laboratories has revealed a large number of hidden 
hybrids, or * crypthybrids,” which are quite constant in their characters, 
and are recognised by systematists as good species, but differ from normal 
Species in the fact that their reproductive cells are to a greater or less 
‘degree abortive. Such facts, it is contended, invalidate the mutation 
hypothesis of De Vriese. It would be interesting to see how far these 
‘observations are applicable to hybrid Orchids, which are certainly common 
in nature, while materials for observation abound in almost every Orchid 
collection. 
