MarcH, 1915.] THE ORCHID REVIEW. 67 
of this plant which was bent towards the ground and had dehisced upon 
the soil. Its seeds had germinated. Upon studying their structure he 
saw that they were infected by a fungus, in all probability the same as that 
upon the roots of the parent plant. This happy observation shed a ray of 
light ; it explained all the failures in cultivation experienccd by growers, as 
well as the reason for their success when they placed the seeds about the 
‘base of the mother plant. 
- Some interesting applications of the discovery to cultural methods are 
then described, and objections answered, and it is remarked: ‘It could 
not be anticipated that the biology of these plants was so extraordinary. 
They are in short, plants that are normally diseased, which not only 
accommodate themselves to their parasites but are unable to exist without 
them.” 
At present three species of these fungi have been described, one which 
inhabits the roots of Cypripediums, Cattleyas, and Lelias; another which 
is associated with species of Phalaenopsis and Vanda, and a third restricted 
to Odontoglossums. ‘‘ These fungi, ordinarily parasites, can be cultivated 
away from their usual host upon an artificial medium. It is then found 
that their threads have the property of rolling upon themselves into a ball, 
so that under artificial conditions they conduct themselves in the same 
manner as in the cells of the host which they have invaded in the usual 
fashion.” 
Any bearing the facts recorded may have upon evolutionary theory is 
limited to the concluding paragraph, where it is remarked: ‘‘ At present 
too much attention is given to the study of hybrids. The Mendelian laws, 
so long forgotton, and recently brought to light by the work of De Vries, 
Tschermak, Correns, and Bateson, would lead one to believe that the key 
to the riddle of evolution had been found. These laws, it must be stated, 
are applicable to very simple cases, such as that of two varieties which 
differ from each other by one or a small number of characters. The 
characters of their offspring are then subject to indisputable mathematical 
laws. They do not seem applicable, at least at the present moment, to 
cases of two parent species of an offspring, differing from each other by 
Numerous characters. If even these complex cases could be cleared up and 
feconciled with Mendelian principles, the result would be a theory eat 
€volution takes place only in the ovule. Can we admit that an exterior 
influence can never cause the appearance of new characters? Upon this 
All that has been set forth above 
there can be no division of opinion. 
which is in accordance 
with regard to the Orchids plead a contrary case, 
with the theory set forth by Lamarck, the famous disciple of Buffon.” 
_ It will thus appear that M. Constantin favours the view so ably defended 
by Prof, Dendy (see pp. 290-295 of our last volume). 
