Note. 
5 2 3 
If the mother-tuber forms mycorhiza, it can produce a full-grown offset which remains 
dormant during the winter and develops the inflorescence axis in the spring of the 
next year. Otherwise, the offsets cannot grow larger than the mother-tuber, and 
under this condition the offsets become smaller and smaller in successive generations, 
until they are so much reduced in size and deficient in food materials as to be 
incapable of further multiplication. 
The tubercles cultivated in the pot with sand, loam, or humus soil produce, as in 
the field, numerous offsets, but none of them can reach the flowering stage. This 
shows that they have no ability to provide themselves with nutriment from the 
surrounding medium. 
The usually saprophytic development of Ar miliaria mellea , the extremely reduced 
vegetative organ of Gastrodia , and the cytological features involved in the symbiosis 
lead us to the view that the reciprocal exchange of nutritive substances between the 
two organisms is not equal, i. e. the fungus becomes the victim of the Orchid, perhaps 
receiving from the latter but little benefit for its whole organization. Therefore, 
it appears probable that physiologically the relation of Gastrodia to the fungus 
is similar to that of subterranean holoparasites to their host roots — Gastrodia is 
parasitic on the fungus. 
The chief reserve material stored in an adult tuber is starch. The amyloplast 
contains a heavily staining body of nuclear nature, whose structure changes at 
successive stages. 
A full account of this subject, with illustrations and references to the literature, 
will appear in the ‘Journal of the College of Agriculture, Imperial University of 
Tokyo 
Agricultural College, Tokyo, 
February , 1911. 
S. KUSANO. 
